The Universal Calculation Engine
The Universal Calculation Engine
CategoryLENGTH
Formula—
Quick Reference — Common Conversions
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Calculators

Use these tools for math, money, health, and everyday life. Math covers basic and scientific calculator, percentage, average, fraction, statistics, probability, number tools, geometry, and algebra. Finance includes tip, loan, and mortgage. Business has ROI and break-even. Investing & Trading and Real Estate link to investment and property calculators. Architecture, Construction, HVAC, and Plumbing offer trade and building calculators. Health covers BMI, BMR, calorie, fitness, pregnancy, and lifestyle. Tools & Daily includes date & time, travel, outdoors, kitchen, school, size converters, and random generators. Energy, Solar, Electrical, Mechanical, and Science & Engineering cover power, solar, and technical calculations. Search or pick a category below to start.

Tools by category

Investing & Trading

Use these tools for portfolio growth and active trading. Portfolio & Growth covers investment calculator, dollar cost average, portfolio allocation, TVM, ROI, investment return, dividend income, and portfolio performance. Trading Tools helps with position size, risk-reward, trade risk, options profit, P&L, leverage, margin, liquidation price, drawdown, and crypto/currency profit. Journal & Projects includes trade journal summary and projects & playbooks. Search or pick a category below to start.

Tools by category

Calculator
Basic arithmetic • send result to unit converter
0
History
No calculations yet
Scientific Calculator
Trig, logarithms, powers, constants

Scientific mode is available inside the Calculator. Toggle it with the Scientific button above the keypad.

Time Zone Converter (Meeting Planner)
Convert a date/time between UTC offsets. Use Meeting Planner to see one time in multiple zones side‑by‑side.
Result
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Meeting Planner — same time in multiple zones
Shoe Size Converter
Convert between US Men, EU, and UK sizes
Result
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Clothing Size Converter
Convert between US, EU, and UK clothing sizes
Result
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Ring Size Converter
Convert between US ring size and inner diameter (mm)
Result
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Bra Size Calculator
Band + bust measurement → US / UK cup and band size
Percentage Calculator
Common phrases, percentage difference, and increase/decrease by percent.
What is X% of Y?
Result
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Formula: Result = (X/100) × Y
X is what % of Y?
Percentage
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Formula: Result = (X / Y) × 100
Percentage Change (X → Y)
Change
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Type
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Formula: Change % = ((Y − X) / X) × 100
X is Y% of what?
Whole
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Formula: Whole = X / (Y/100)
Percentage Difference
Difference
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Increase or Decrease by Percent
Result
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Percent Error
Percent Error
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Formula: Percent Error = |measured − accepted| / |accepted| × 100
Fraction Calculator
Addition, subtraction, multiplication, division, simplification, and conversion between fractions and decimals.
Fraction
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Decimal
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Mixed Number
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Statistics Calculator
Mean, median, mode, standard deviation & more
Area & Volume
Geometric area and volume by shape. Real-time calculation.
Result
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Surface Area
Surface area of sphere, cone, cube, cylinder, prism, capsule, cap, frustum, ellipsoid, pyramid. Same unit for all dimensions.
Formula
Surface Area
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Average Calculator
Mean, weighted average, and rolling totals
Random Number Generator
Generate random integers or decimals
Generated Numbers
Random Name Generator
Generate random first names, last names, or full names
Random Color Generator
Generate random colors (HEX, RGB) with optional copy
Lorem Ipsum Generator
Generate placeholder text — words, sentences, or paragraphs
Coin Flip
Flip a virtual coin — Heads or Tails
Dice Roller
Roll one or more dice (d4, d6, d8, d10, d12, d20)
Random Card Generator
Draw one or more random playing cards
Random Letter Generator
Generate random letters (A–Z or a–z)
Random Country / City
Pick a random country or major city
Random Date Generator
Generate random dates within a range
Spin the Wheel
Enter options (one per line), then spin to pick one at random
Baby Name Generator
Generate random baby names by style
Business Name Generator
Random business or brand name ideas
Fantasy Name Generator
Generate names for characters, places, or creatures
Pet Name Generator
Cute and catchy names for dogs, cats, and other pets
Random Username Generator
Generate unique usernames (adjective + noun + numbers)
Fake Credit Card Generator
Generate Luhn-valid test card numbers. For development/testing only; do not use for real payments.
Carbon Footprint
Miles flown and car miles → rough CO₂ estimate
Weird Units Converter
Turn everyday values into fun equivalents: distances, weights, areas, volumes, speeds, and temperatures.
Love Calculator
Fun compatibility score based on two names (for entertainment only)
Golf Handicap Calculator
Course handicap from handicap index and slope rating (USGA-style)
Formula: Course Handicap = Index × (Slope/113) + (Course Rating − 72)
Wind Chill Calculator
Feels-like temperature from air temperature and wind speed (NWS formula)
Formula: NWS: 35.74 + 0.6215×T − 35.75×V^0.16 + 0.4275×T×V^0.16 (°F, mph)
Heat Index Calculator
Feels-like temperature from air temp and relative humidity (NWS)
Formula: Rothfusz regression (polynomial in temp °F and humidity %)
Dew Point Calculator
Dew point from temperature and relative humidity (Magnus formula)
Formula: Magnus: γ = ln(RH/100) + (a×T)/(b+T); T_dp = (b×γ)/(a−γ); a=17.27, b=237.7
Instagram Font Generator
Convert text to fancy Unicode styles — copy and paste into Instagram, bios, and social posts
Result
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Hashtag Generator
Generate hashtags from topics or keywords (comma-separated)
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Click to copy all

Bio Generator
Short Instagram-style bios — pick a style and generate
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Emoji Picker
Click an emoji to copy it

Click to copy

Home & Rent Affordability
How much house or rent you can afford: income and debt → max home price or max monthly rent. Combines house affordability, rent affordability, and DTI.
Affordability type
Income & debt
Loan & costs
DTI rule
Reverse: target home price
Comparison
Price tiers
Monthly payment at max price
Required income (target price)
Financial health
Approval strength
Lifestyle impact
Down payment
Income comparison
Budget breakdown
Loan & Mortgage
Conventional, FHA & VA loans with taxes, insurance, PMI/MIP, payoff, refinance and APR views.
1) Property & Loan Basics
2) Program-specific
Conventional — PMI
3) Closing Costs & Cash-to-Close
4) Monthly Ownership Costs
5) Payment Strategy
6) Scenario Settings

Show amounts as:
A) Real Monthly Cost

Payment breakdown
B) Program Cost Impact

C) Cash to Close

D) Loan Summary & Payoff

E) Amortization & Milestones

F) Extra Payments & Biweekly

G) Equity Projection

Charts
Balance & payments over time
Formula: PMT = P × (r(1+r)^n) / ((1+r)^n − 1); r = annual rate/12, n = months
Sales Tax Calculator
Calculate tax amount and final price
Reverse: Find Pre-tax Price
VAT Calculator
Add or remove VAT (value-added tax) from a price
Formula: Add VAT: amount_incl = amount_excl × (1 + rate); Remove: amount_excl = amount_incl / (1 + rate)
Tip Calculator
Split bills and calculate tips
Bill vs Tip
Discount Calculator
Find sale price, savings, and effective discount
Find Discount % from Prices
ROI Calculator
Return on investment and annualized ROI
Initial vs Return
Investment Return Calculator
Was this investment good? ROI, IRR, payback, grade, and comparison to market.
Bond Calculator
Price, yield to maturity, coupon — enter known values to solve for the unknown
Formula: Price = PV(coupons) + PV(par); PV(coupons) = c×(1−(1+y)^(−n))/y; PV(par) = par/(1+y)^n
Price Increase
Old and new price → absolute and % change
Revenue Growth
Starting and ending revenue → growth %, CAGR, and yearly breakdown
Creator & Ad Revenue Calculator
One calculator for RPM (YouTube/TikTok/etc.), AdSense, CPM, and affiliate revenue. Pick a mode and enter your numbers.
Debt Payoff Planner
Multi-loan payoff: use extra payment to target one strategy (e.g. lowest balance first); when a loan is paid off, its min payment rolls to the next.
Loan NameBalance ($)APR (%)Min. Payment ($/mo)
Per-Loan Results
Strategy Comparison
Balance Over Time
Month-by-Month Payment Schedule
Student Loan Calculator
Standard repayment: balance, rate, term → monthly payment and total interest
Auto Loan Calculator
Vehicle financing with trade-in, down payment, taxes & fees
Total PriceMonthly Payment
Principal vs Interest
Balance, Interest & Payment Over Time
Amortization Schedule
AnnualMonthly
Car Affordability
Income and existing debt → recommended max car payment and price you can afford
We also show 10–15% of income as a rule-of-thumb for car payments.
Max Loan Amount
Given a monthly payment, find the maximum loan amount you can afford
Auto Lease Calculator
Monthly lease payment, cost breakdown, and comparison to buying the same car
Total PriceMonthly Payment
Lease
If purchased under the same conditions
Lease payment breakdown

Doc, title, and registration fees are not included. Leases often have acquisition, security deposit, and disposition fees; in practice leasing can cost more than this estimate.

Terms

Money Factor — The lease equivalent of an interest rate, usually shown as a decimal (e.g. 0.00208). Multiply by 2,400 to get approximate APR. Set by the lessor; lower is better.

Interest Rate (APR) — Annual percentage rate. Same cost of money as money factor: APR ÷ 2,400 ≈ money factor.

Residual Value — Estimated value of the vehicle at the end of the lease (set by the lessor). A higher residual usually means a lower monthly payment but a higher amount due if you buy the car at the end.

Cash Back or Low Interest
Compare cash back rebate vs low interest rate on an auto loan
Cash Back Offer
Low Interest Offer
Auto & Loan Details
With Cash Back Offer
With Low Interest Offer
Loan Comparison
Compare two loans by payment, total cost, and interest
Loan A
Loan B
Credit Card Payoff
How long to pay off a credit card with fixed monthly payments
Home Equity & HELOC
Available equity, Home Equity Loan vs HELOC comparison, costs over time, stress tests, and a clear recommendation.
Your home
Home Equity Loan
HELOC
Best loan payment plan
HELOC draw & repayment
Total cost over time
Net cash & equity
Payment stress test
HELOC sensitivity
Equity vs loan balance
Payment timeline
Recommendation
Rent vs Buy
Compare average monthly cost of buying vs renting over 1–30 years; break-even and chart
Home purchase
Home rent
Your info
Chart
Average cost by stay length
Staying LengthAverage Buying CostAverage Renting Cost
MonthlyAnnualMonthlyAnnual
Assumptions: fixed-rate fully amortizing mortgage with level payments; investment return is applied to upfront cash as annual compound growth; property tax and insurance grow using the inputs above; tax savings are approximated as (mortgage interest + property tax) × (federal + state marginal rate).
APR Calculator
Effective APR including fees (loan amount, fees, term, rate)
Paycheck & Overtime Calculator
Estimate take-home pay: gross or hours + rates, federal & state tax, FICA, 401(k). Uses 2026 federal brackets.
401(k) Growth Simulator
Project savings to retirement age with employer match & inflation
Balance Over Time
Retirement Master Planner
Project 401(k), IRA, Roth IRA & taxable accounts. See if you're on track and compare scenarios.
Retirement readiness—
Projected savings at retirement—
Estimated monthly income (4% rule)—
Desired retirement income—
Portfolio projection
Hover for values at each age.
Income replacement
Account breakdown over time
Scenario comparison

Compare up to 3 scenarios. Edit inputs and click "Add scenario" to capture current inputs as a scenario.

Retirement Income Planner
See total monthly retirement income: Social Security, pension, annuities & other. Compare claiming ages and pension vs lump sum.
Total retirement income—/ month
Status—
Annual—
Lifetime (to age)—
Income vs target
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Monthly income by source
Income over time (by age)
Social Security: benefit by claim age (62–70)
Scenario comparison

Add current inputs as a scenario to compare (e.g. SS at 62 vs 70).

Withdrawal & Longevity Planner
Project withdrawals over time, see how long savings last, and understand RMD rules. Reassuring and solution-focused.
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Age money runs out—
Monthly income supported—
Years supported—
Total lifetime withdrawals—
Balance at life expectancy—
RMD impact—
Longevity—
Portfolio balance over time
Planned withdrawal vs RMD
Annual withdrawal
Account depletion (order: Taxable → Traditional → Roth)
Spending taxable first preserves tax-advantaged growth. Roth last gives most flexibility.
Scenario comparison

Add current inputs as a scenario (e.g. lower withdrawal vs higher).

Retirement Decision Optimizer
Unified decision engine: compare strategies, see success probability, and get recommendations. Integrates savings, income, and withdrawal logic.
Retirement Readiness Score
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/ 100
Probability of success
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Optimization recommendations
    Recommended retirement age—
    Recommended SS claim age—
    Safe spending level—
    Income stability—
    Wealth projection
    Income vs spending
    Strategy comparison

    Compare up to 5 strategies. Use sliders or inputs and click "Add strategy" to capture.

    Amortization Schedule
    Full month-by-month schedule with CSV download
    Principal & Interest Over Time
    Investment Calculator
    Money growing over time: lump sum, recurring contributions, savings goal, CD, or full investment growth
    Formulas: Lump sum: FV = PV × (1+r)^n; Recurring: balance each period = balance×(1+r) + contribution; Savings goal: solve for n or PMT in FV of annuity
    Where your final value comes from
    Growth over time
    Year-by-year
    YearDepositsInterestEnd balance
    Inflation Calculator
    Purchasing power over time using average annual rate

    💡 US avg: ~3.2% (1913–2024)  ·  2000s: ~2.6%  ·  2010s: ~1.8%  ·  2020–24: ~5.1%

    Formula: Future value = Amount × (1 + inflation_rate/100)^years
    Purchasing Power Over Time
    College Cost Calculator
    Future cost of college and how much to save (with inflation)
    GDP Calculator
    GDP growth over time: initial GDP and annual growth rate → future GDP
    TVM Solver
    Solve for PV, FV, PMT, N, or I/Y — 5-key time value of money

    💡 Use negative values for cash outflows. Leave the field you're solving for blank.

    Salary Converter
    Enter either annual salary or an amount per period — converts to all other equivalents.
    BMI & BMR Calculator
    Body Mass Index and Basal Metabolic Rate — one form, both results. Uses Units (Metric/Imperial) from header.
    BMR (Mifflin-St Jeor)
    Body composition
    Formulas: BMI = weight(kg)/height(m)²; BMR (Mifflin-St Jeor): male 10×wt+6.25×ht−5×age+5, female …−161
    Body Surface Area (BSA)
    Height & weight → body surface area using Mosteller, Du Bois, and Haycock formulas.
    Calorie / TDEE Calculator
    Total Daily Energy Expenditure and calories burned per activity
    Calories burned (single activity)
    Body Fat % Calculator
    Tape-method body fat using Navy / Army formulas with fitness and branch categories.
    GFR Calculator (Kidney Function)
    Estimated glomerular filtration rate (eGFR) — CKD-EPI formula. For reference only; not a diagnosis.
    Formula: CKD-EPI: eGFR = 141 × min(SCr/κ,1)^α × max(SCr/κ,1)^(−1.209) × 0.993^age
    Ideal Weight Calculator
    Four established formulas (Devine, Robinson, Miller, Hamwi)
    Height Calculator (Adult Height Predictor)
    Estimate child's adult height from current height and age (Khamis-Roche method or mid‑parental)
    Macro Calculator (Ideal Macros for Goal)
    Protein, carbs & fat targets from your TDEE and diet goal
    Protein Calculator
    Daily protein target from bodyweight and goal (rough guideline only)
    Pregnancy Tracker
    Gestational age, trimester, EDD, and week-by-week milestones
    Due Date Calculator
    Naegele's rule (LMP) and IVF Day-3 / Day-5 transfer methods
    Conception Window & Ovulation
    From due date → fertile window; or from last period → ovulation & next period
    Pregnancy Weight Gain
    IOM 2009 guidelines by pre-pregnancy BMI — single and twin pregnancies
    Pace Calculator
    Running pace, distance & time — enter any two to find the third
    Steps to Calories Calculator
    Steps, step length, and weight → distance and approximate calories burned (walking)
    Age Calculator
    Exact age, workdays lived, next milestone birthday, and more
    Days Between Dates
    Days, weeks, months, and years between two dates
    Military Time Converter
    Convert between 24‑hour and 12‑hour (AM/PM) time formats.
    Countdown Timer
    Set a target date and time; see time remaining (updates every second)
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    Stopwatch
    Elapsed time with Start, Pause, and Reset
    00:00:00.0
    Sunrise / Sunset Calculator
    Sunrise and sunset times for a date and location (latitude/longitude)
    Moon Phase Calculator
    Moon phase, illumination %, and age in days for any date
    Hiking Time Estimator
    Estimate hiking time using Naismith’s rule with options for pace and conditions
    Calories Burned Hiking
    Estimate calories burned on a hike from distance, elevation, and body weight
    Water Requirement Calculator
    Day‑hike or backpacking: estimate water needed from hours, heat, and exertion level
    Survival Water Calculator
    Minimum daily water per person for survival scenarios (estimate only — not medical advice)
    Camp Cooking Calculator
    Estimate food weight and stove fuel for camping trips
    Firewood Requirement Calculator
    Estimate bundles or cubic feet of firewood needed for camping
    Backpack Weight Calculator
    Total pack weight and % of body weight for backpacking or thru‑hikes
    Elevation Gain Calculator
    Convert between feet and meters and summarize total elevation gain per mile or km
    Pace Count Calculator
    Estimate how many double‑steps (paces) you take per 100 m or 100 yd and convert distance ↔ pace count
    Hypothermia Risk Calculator
    Approximate outdoor hypothermia risk category from air temp, wind, clothing, and wetness (informational only)
    Frost Risk Calculator
    Garden / crop frost risk from forecast low, dew point, and exposure (simplified)
    Estimated Time of Arrival (ETA)
    Distance and speed → travel time and arrival clock time
    Horizon Distance Calculator
    Estimate distance to the horizon from eye height (spherical Earth approximation)
    Hull Speed Calculator
    Displacement hull speed from waterline length
    Boat Speed Calculator
    Speed made good from distance and elapsed time (nautical or statute)
    True vs Apparent Wind Calculator
    Boat speed and true wind → apparent wind speed and angle (simplified)
    Course & Bearing Calculator
    Compute course and distance between two coordinates (great‑circle approximation)
    Signal Visibility Distance
    Estimate how far away a light or signal can be seen from given heights
    Nautical Unit Converter
    Quick conversions between nautical miles, knots, km, and mph
    Coordinate Converter
    Latitude/longitude: decimal degrees ↔ degrees / minutes / seconds (DMS).
    Time Calculator
    Add or subtract hours, minutes, and seconds
    Hours Calculator
    Calculate hours worked and weekly pay
    Recipe Scaling
    Scale ingredient amounts when changing servings or pan size
    Use square inches or cm² (e.g. 8×8 in pan → 64 in², 9 in round → ~64 in²).
    Kitchen Converter
    Convert between cups, grams, spoons, and more, using ingredient-specific densities.
    Rice & Pasta Planner
    How much dry rice or pasta and water do you need for a crowd?
    Party Food & Drink Planner
    Estimate how much food and drink to buy for your event.
    GPA Calculator
    Weighted GPA from course grades and credit hours
    CourseGradeCredits
    Grade Calculator
    Weighted final grade from assignments
    AssignmentScoreMax ScoreWeight (%)
    Password Generator
    Generate secure, random passwords
    Check Password Strength
    Bandwidth Calculator
    Data size and speed → time to download; or size and time → required speed
    Token Counter (OpenAI, Claude)
    Estimate token counts for OpenAI and Claude from text (character/word-based approximation)
    AI Cost Calculator
    Estimate API cost from input/output token counts for OpenAI and Anthropic models
    Unit Price
    Compare price per unit (e.g. $/oz, $/kg)
    Quote Generator
    Simple project quote from rate, hours, discount, and tax
    Invoice Generator
    Quick invoice totals from subtotal, discount, and tax (plus due date)
    Trip Cost Calculator
    Trip cost, fuel needed, or MPG from distance and fuel used. Use for drive planning and travel budgets.
    Coins to Cash
    Counts of US coins → total value in dollars.
    TCO Calculator (Total Cost of Ownership)
    Vehicle or asset: purchase price + annual costs over years → total cost and cost per mile
    EV Charging Cost Calculator
    Charging time, energy needed, and cost from battery size, power, and electricity rate — plus optional cost per mile and per month
    Speed Calculator
    Distance and time → speed; or speed and time → distance
    Engine Horsepower Calculator
    Estimate vehicle HP from weight and 1/4‑mile trap speed (elapsed time optional)
    Tire Size Calculator
    Sidewall height, revs per mile, and diameter from tire dimensions (e.g. 225/45R17)
    Rounding
    Round to N decimal places or significant figures
    Scientific Notation Calculator
    Convert between decimal and scientific notation
    Big Number Calculator
    Add, subtract, multiply, divide large integers (beyond normal precision)
    Result
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    Half-Life Calculator
    Decay: N = N₀ × 0.5^(t / t½). Enter any three to find the fourth.
    Formula: N = N₀ × 0.5^(t / t½)
    Slope Calculator
    Slope and line equation from two points
    Formula: m = (y₂ − y₁) / (x₂ − x₁); line: y = mx + b
    Distance Calculator
    Distance between two points (2D, 3D, or latitude/longitude on Earth)
    Point 1:
    Point 2:
    Distance
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    Formula: d = √((x₂−x₁)² + (y₂−y₁)²) [add +(z₂−z₁)² for 3D]
    Matrix Calculator (2×2)
    Determinant, inverse, multiply two 2×2 matrices
    Formula: det = a₁₁a₂₂ − a₁₂a₂₁; A⁻¹ = (1/det)×adj(A); C = A×B
    Number Sequence Calculator
    Analyze a list, or compute Arithmetic / Geometric / Fibonacci
    Sample Size Calculator
    Find sample size n or margin of error E for proportion
    Formula: n = z²×p(1−p)/E²; with finite population N: n = n∞/(1+(n∞−1)/N); E = z×√(p(1−p)/n) or with FPC: ×√((N−n)/(N−1))
    Probability Calculator
    Two events (P(A), P(B)) or normal distribution (area between bounds)
    Formulas: Two events: P(A∪B)=P(A)+P(B)−P(A∩B); P(AΔB)=P(A)+P(B)−2P(A∩B); Series: P(all)=p^n, P(at least one)=1−(1−p)^n; Normal: P = Φ((Rb−μ)/σ) − Φ((Lb−μ)/σ)
    Z-Score Calculator
    z = (x − μ) / σ
    Formula: z = (x − μ) / σ
    Confidence Interval Calculator
    Mean ± Z × (s / √n). For population mean from sample.
    Formula: CI = x̄ ± z × (s/√n); margin = z × (s/√n)
    Ratio
    Simplify ratio, solve proportion, or ratio to percentage
    Linear & Quadratic Equation
    One linear (ax + b = c), quadratic ax² + bx + c = 0, or linear systems 2×2 / 3×3

    Solves ax + b = c → x = (c − b) / a

    Permutation & Combination
    nPr and nCr
    Prime & Factors
    Check prime, list factors, LCM, GCD
    Ohm's Law
    V = I × R — enter any two to find the third and power
    Formula: V = I × R; P = V × I
    Decibel (dB)
    dB to power/voltage ratio and back
    Formula: Power ratio = 10^(dB/10); Voltage ratio = 10^(dB/20)
    Density
    Mass, volume, density — enter two to find the third
    Formula: ρ = m / V (density = mass / volume)
    Molarity Calculator
    Molarity (M), moles, volume — enter two to find the third
    Formula: M = n / V (molarity = moles / volume in L)
    Molecular Weight Calculator
    Sum atomic masses from chemical formula (e.g. H2O, CaCO3)
    Dilution (C₁V₁ = C₂V₂)
    Enter three of concentration/volume to find the fourth
    Formula: C₁V₁ = C₂V₂
    Solution Mixing
    Mix two solutions to get final concentration
    Mass Percent
    Mass of solute / total mass × 100
    ppm / ppb
    Parts per million or billion from mass or concentration
    Moles (mass ↔ moles)
    n = m / M (moles = mass / molar mass)
    Formula: n = m / M
    Limiting Reactant
    Compare moles / stoichiometric coefficient to find limiting reactant and theoretical yield
    Ideal Gas Law (PV = nRT)
    Enter three of P, V, n, T to find the fourth. R = 0.08206 L·atm/(mol·K)
    Formula: PV = nRT
    Gas Density
    ρ = PM / (RT) — density from pressure, molar mass, temperature
    Gas Cylinder Duration
    Estimate time until cylinder empty at given flow rate (simplified: ideal gas)
    pH from [H⁺]
    pH = −log₁₀[H⁺]; enter [H⁺] in mol/L
    Formula: pH = −log₁₀[H⁺]
    pH Adjustment
    Amount of strong acid/base to add to reach target pH (simplified: pure water or buffer)
    Buffer (Henderson–Hasselbalch)
    pH = pKa + log₁₀([A⁻]/[HA])
    Specific Gravity
    SG = ρ / ρ_ref (default ρ_ref = 1000 kg/m³ for water)
    Molar Mass to Density
    Density from molar mass and molarity (ρ ≈ M × C for dilute aqueous; or enter mass/volume)
    Batch / Scale Recipe
    Scale recipe by factor: new amount = base amount × scale
    Yield
    Percent yield = (actual / theoretical) × 100
    Purity
    Purity % = (pure mass / total mass) × 100
    Faraday's Law
    Q = n_e × F; charge from moles of electrons (F ≈ 96485 C/mol)
    Electroplating
    Mass deposited: m = (I × t × M) / (n × F); I=current (A), t=time (s), M=molar mass, n=electrons per ion
    Chlorine Dosing
    Mass or volume of chlorine needed for target ppm (e.g. pool)
    Water Hardness
    Convert Ca²⁺ and Mg²⁺ to mg/L as CaCO₃ equivalent
    Alkalinity
    Alkalinity as mg/L CaCO₃ from titrant volume and normality
    Chemical Dosing
    Dose (mg/L or g/L) from target concentration and volume
    ABV (Alcohol by Volume)
    Simple: ABV ≈ (OG − FG) × 131.25 (OG/FG as specific gravity)
    Sugar Concentration (Brix / Plato)
    Brix ≈ Plato for dilute solutions; % sucrose by mass
    Coffee Ratio Calculator
    Coffee : water ratio (e.g. 1:15, 1:17) — enter one of coffee or water to get the other
    Alcohol Dilution Calculator
    Dilute spirit to target ABV — how much water (or diluent) to add
    Beam Deflection
    Simply supported beam with center point load or uniform load → max deflection
    Formula: Point load: δ = PL³/(48EI); Uniform: δ = 5wL⁴/(384EI)
    Stress & Strain
    Force and area → stress; length change → strain and approximate modulus
    Formula: σ = F/A (stress); ε = ΔL/L₀ (strain); E = σ/ε (modulus)
    Bending Moment Calculator
    Force × perpendicular distance → bending moment (M = F·d). Supports N, kN, lbf, kip and m, mm, ft, in.
    Formula: M = F × d (bending moment)
    Load Converter
    Convert between force/load units: newton (N), kilonewton (kN), pound-force (lbf), kip
    Enter exactly one value; the others will be calculated.
    Column Buckling & Load Capacity
    Slenderness ratio, end conditions, Euler buckling load, and safety factor → capacity check and failure mode warning
    Formula: P_cr = π² E I / (K·L)²; λ = K·L / r
    Retaining Wall Stability Simulator
    Active earth pressure, sliding and overturning checks, bearing pressure, optional water table
    Structural Project Risk Analyzer
    Load uncertainty, safety factor sensitivity, material cost volatility, and code compliance → risk rating
    Load uncertainty
    Safety factor sensitivity
    Material cost volatility
    Code compliance flags
    Moment of Inertia
    Common shapes (rectangle, circle, hollow circle) → second moment of area
    Thermal Expansion
    Length, coefficient, and temperature change → change in length and new length
    Fluid Flow
    Pipe diameter with either flow rate or velocity → solve the other
    Provide diameter and at least one of flow rate or velocity; the other will be calculated.
    Acceleration
    a = Δv / Δt — enter two to find the third
    Formula: a = Δv / Δt
    Stopping Distance
    Reaction distance + braking distance = total stopping distance
    Formula: Reaction d = v×t; Braking d = v²/(2a); Total = reaction + braking
    Free Fall
    Time, velocity, and height — enter two to find the third (g = 9.81 m/s²)
    Formula: v = √(2gh); t = √(2h/g); h = ½gt²
    Projectile Motion
    Initial speed and launch angle → range, max height, flight time (g = 9.81 m/s²)
    Formula: R = v₀² sin(2θ)/g; H = v₀² sin²θ/(2g); T = 2v₀ sinθ/g
    Force (F = ma)
    Force, mass, acceleration — enter two to find the third
    Formula: F = m × a
    Weight
    W = m × g (default g = 9.81 m/s²)
    Formula: W = m × g
    Kinetic Energy
    KE = ½mv² — enter two to find the third
    Formula: KE = ½ m v²
    Potential Energy
    PE = mgh — enter two to find the third (g = 9.81 m/s²)
    Formula: PE = m × g × h
    Work
    W = F × d (force along displacement) — enter two to find the third
    Formula: W = F × d
    Hydrostatic Pressure
    P = ρgh — pressure at depth (liquid)
    Formula: P = ρ × g × h
    Buoyancy
    F_b = ρ_fluid × V × g — buoyant force on submerged volume
    Formula: F_b = ρ × V × g
    Heat Energy
    Q = mcΔT — heat to change temperature
    Formula: Q = m × c × ΔT
    Wave Equation
    v = f × λ — speed, frequency, wavelength (enter two to find the third)
    Formula: v = f × λ
    Centripetal Force
    F = mv²/r (or F = mω²r) — force for circular motion
    Formula: F = m v² / r
    Friction Force
    F_f = μ × N — sliding friction
    Formula: F_f = μ × N
    Momentum
    p = mv — enter two to find the third
    Formula: p = m × v
    Efficiency
    η = (useful output / input) × 100%
    Formula: η = (output / input) × 100%
    Load & Demand
    Connected loads and demand factor → service load and estimated service current (approximate)
    For NEC-compliant designs, always verify against the actual code tables for your occupancy and jurisdiction.
    Service Load Calculation Engine (NEC)
    Residential & small commercial: demand factors, continuous vs non-continuous, EV, generator interlock, 200A/400A recommendation.
    System
    General loads (VA)
    Appliances & HVAC
    Optional
    Code reference: NEC Art. 220. Verify against current code and jurisdiction.
    Arc Flash Risk Estimator
    Fault current from transformer; working distance → simplified incident energy and PPE category suggestion.
    Simplified estimator. For compliance use dedicated arc-flash study software.
    Panel Schedule Builder
    Build a panel schedule: breakers, phases, neutral load, AFCI/GFCI. Print or copy.
    Panel
    Breakers
    Conduit Fill & Derating
    Mixed sizes, THHN/XHHW, ambient & bundling correction, max fill, conduit recommendation.
    NEC max fill: 53% (1), 31% (2), 40% (3+). Derating per 310.15(B).
    Lighting Design
    Simple lumen method: room area, target illuminance, and fixture lumens → number of luminaires
    Cable Pulling Tension
    Total pull tension and bend radius → sidewall bearing pressure
    Material Takeoff & Cost
    Up to three line items → extended cost and total (quick estimating aid)
    Electrical Job Cost & Margin
    Labor rate, material cost, overhead, profit margin → price to charge. Quote comparison mode.
    Labor
    Materials & overhead
    Margin
    Quote comparison (optional)
    Code Cross-Reference
    Organize code sections for a project and quickly highlight matches (does not contain code text)
    Water Pipe Sizing
    Flow, length, and limits → recommended nominal size (using Hazen–Williams approximation)
    Rule-of-thumb sizing only. For critical systems, verify against local plumbing code tables.
    Gas Pipe Sizing
    Flow and velocity limit → approximate nominal gas pipe size (velocity-based)
    Uses simple velocity-based sizing. Always confirm with official gas-sizing tables for your code and pressure range.
    Drain, Waste & Vent (DWV)
    Total fixture units and slope → rule-of-thumb horizontal branch and building drain sizes
    Sizing is approximate and for quick checks only. Confirm with your plumbing code (e.g. IPC or UPC) tables for occupancy and fixture mix.
    Pressure Loss
    Water line diameter, length, and flow → velocity and friction loss (Hazen–Williams)
    Pump Curve Analyzer
    Required vs. pump BEP flow/head → simple match index (for quick screening only)
    Fixture Unit Summary & Layout
    Up to four fixture types → total fixture units and suggested building drain size (rule-of-thumb)
    Pipe Sizing Engine
    Fixture units, material, and run → design flow, velocity check, and smallest pipe that meets limits (conceptual)
    Uses a simplified demand factor model and Hazen–Williams. For permit work, verify against your plumbing code’s sizing tables.
    Water Pressure Drop Planner
    Up to three pipe segments + elevation → friction loss, static loss, and booster pump suggestion
    Tool is approximate and assumes full-flow Hazen–Williams behavior. Always verify with detailed design calculations.
    Drainage & Vent Stack Planner
    Fixture units, slope, and trap arms → suggested branch/stack sizes and code-style checks (conceptual)
    Uses generic IPC/UPC-style rules of thumb. Always confirm layout and sizing with your local plumbing code.
    Tankless Water Heater Sizing
    Simultaneous fixtures, inlet temperature, and climate → required GPM and BTU/hr
    Simultaneous fixtures
    Assumes typical low‑flow fixtures. For exact sizing, use manufacturer charts for your model and gas type.
    Plumbing Job Estimator
    Materials, labor, overhead, margin, and emergency markup → recommended quote and profit
    Base costs
    Emergency / after‑hours
    GPM & LPM Converter
    Convert between gallons per minute, liters per minute, and cubic meters per hour
    Enter exactly one value; the others will be calculated.
    Water Pressure Converter
    Convert between psi, bar, kPa, and meters of water column
    Enter exactly one value; the others will be calculated. Uses standard freshwater approximations.
    Drain Slope Calculator
    Any two of run, drop, and slope → compute the third for basic drain layout
    Enter any two values; the third will be calculated. Positive slope means flowing “downhill.”
    Tank Volume Calculator
    Rectangular or cylindrical tank dimensions and fill height → volume in ft³, gallons, and liters
    Battery Life
    mAh, voltage, and load → hours of use
    Voltage Drop
    Approximate voltage drop and % for a copper run
    Advanced Voltage Drop Planner
    Multi-segment runs, Cu/Al, temperature, parallel conductors, motor surge, cost comparison, optimize for <3%.
    Wire Size
    Suggest minimum AWG for a circuit based on length, current, and allowed voltage drop
    Power Calculator
    Single- or three-phase: voltage, current, power factor → kW, kVA, and kVAR
    Electricity Cost
    Power, usage hours, and rate → kWh and cost per day, month, and year
    Battery Backup Calculator
    kWh needed to cover a load for a given outage duration (with optional reserve)
    Generator & Backup Power Sizing
    Whole-home loads, startup surge, fuel type, transfer switch, runtime. Residential & light commercial.
    Torque Calculator
    Power and speed → torque (or use torque and speed to get power)
    Bolt Torque
    Preload, diameter, and K-factor → tightening torque
    Gear Ratio
    Driver and driven teeth (or speeds) → gear ratio and speed change
    Motor Speed
    Line frequency, poles, and slip → synchronous and running RPM
    Solar Panel / Savings
    System size, tilt factor, sun hours, and rate → daily, monthly, and yearly kWh and bill savings
    Roof Angle / Tilt Calculator
    Roof pitch or latitude → tilt angle, tilt factor, and seasonal bias notes
    Sun Hours by Location
    Latitude and climate band → approximate average peak sun hours per day
    kWh & Watts Converter
    Any two of power, energy, and hours → compute the third
    Enter any two values; the third will be calculated.
    Solar System Sizing Engine (Residential)
    Monthly usage, climate, roof orientation, and losses → required DC size, panel count, and 20‑year production curve (conceptual)
    Solar ROI & Financial Simulator
    System cost, incentives, escalation, and financing → payback, NPV, and IRR (conceptual)
    Loan scenario (optional)
    Lease scenario (optional)
    Battery Storage Sizing Tool
    Critical loads, outage duration, chemistry, and generator → recommended kWh and module count (conceptual)
    The optimizer also reports the minimum battery size to cover a 12‑hour outage at the entered average load.
    Solar Array Layout Planner
    Roof dimensions, panel size, spacing, and obstacles → estimated rows, strings, and layout summary (conceptual)
    Assumes portrait orientation and simple rectangular roof. For permit drawings, use full layout tools and manufacturer requirements.
    Commercial Solar Feasibility Tool
    Demand charges, TOU rates, incentives, and depreciation → annual savings and simple cash‑flow view (conceptual)
    Solar + EV + Battery Integration Planner
    EV charging, home battery, and solar → annual energy flows, self‑consumption, and autonomy (conceptual)
    EV charging
    Battery
    Rates & net metering
    Resistor Color Code
    4-band or 5-band → resistance and tolerance
    Capacitor Code
    Code → capacitance (pF, nF, µF). Supports 3-digit (e.g. 104), letter suffix (10n, 22p, 4u7)
    Break-Even
    Fixed cost, variable cost, price → break-even units and revenue
    Cost & Revenue vs Units
    Margin vs Markup
    Convert between margin % and markup %; cost and sell price
    Car Depreciation Calculator
    Straight-line or declining balance depreciation schedule
    Car / Vehicle depreciation (simple % pattern)
    Net Worth
    Total assets minus total liabilities
    Commission
    Commission amount from sale amount and rate %
    Budget Calculator
    Income vs spending categories — see totals and surplus/deficit
    Monthly expenses (add rows as needed)
    Options Profit & Break-Even
    Options trade P&L, break-even, and ROI for calls or puts (simplified, not for real-world risk management).
    Position Size (Risk-Based)
    Account size, risk per trade, entry and stop → recommended position size.
    Trade Risk Overview
    Check how much of your account is at risk across open trades (guidance only, not brokerage-grade risk engine).
    Trade Profit & Loss
    Entry, exit, size, and fees → P&L, return %, and outcome color.
    Risk-Reward & Expectancy
    Entry, stop, target, and win rate → R-multiple and expectancy per trade.
    Currency Profit
    Forex/crypto trade P&L in account currency (simplified; ignores swap, funding, and complex pip rules).
    Crypto Profit Calculator
    Crypto trade P&L: entry, exit, size, and fees in account currency.
    Liquidation Price Calculator
    Leveraged or margin position → price at which you get liquidated (simplified).
    Leverage & Exposure
    Account equity and position size → live leverage and exposure (guidance only).
    Margin Requirement
    Position size and margin requirement % → required equity and free margin.
    Drawdown & Recovery
    Peak vs current equity → drawdown %, required return to recover, and suggested risk level.
    Portfolio Allocation Planner
    Total portfolio value and target weights → per-asset dollar allocations.
    Dollar Cost Average Calculator
    Multiple entries at different prices → blended average cost and total position.
    Dividend Income Planner
    Shares and dividend per share → monthly and annual income and yield.
    Portfolio Performance & CAGR
    Starting value, contributions, and current value → total return and CAGR.
    Trade Journal Summary
    Summary stats for your trading journal → win rate, expectancy, and risk insights.
    Investing Projects & Playbooks
    Lightweight local projects tracker for your trades and investing ideas (saved in your browser only).
    Projects are saved locally in this browser only. This is not a brokerage or cloud account.
    Rental Property Calculator
    Full analysis: cash flow, CoC, cap rate, IRR, wealth creation, break-even rent, and deal score. Saves to Deal Comparison so you can compare with other deals.
    Purchase
    Operating Expenses (annual)
    Income
    Hold & Sell
    Wealth Growth
    Cash Flow by Year
    Expense Breakdown
    Deal Finder Mode
    Enter price, rent, and rehab → Calciverse tells you: BUY, NEGOTIATE LOWER, or PASS
    Fix & Flip (Pro)
    Purchase, rehab, ARV, costs, and loan terms → net profit, ROI, offer guidance, and risk
    Rehab Estimator
    Cost per sq ft + detailed line items → total rehab cost and warnings
    70% Rule
    ARV, repairs, profit and costs → maximum allowable, safe, aggressive, and danger offers
    BRRRR Calculator
    Buy, Rehab, Rent, Refinance, Repeat → cash left in, cash out, and infinite return detection
    Airbnb Calculator
    Nightly rate, occupancy, and costs → cash flow, CoC, cap rate, and minimum profitable nightly rate
    Wholesaling Calculator
    ARV, repairs, assignment fee, and buyer profit target → max offer to seller and deal quality
    Mortgage (Investor)
    Investor‑focused mortgage with extra payments and refinance simulation
    Sell vs Keep
    Compare wealth if you sell now vs keep renting, with appreciation and loan paydown
    Deal Comparison & Dashboards
    Compare saved scenarios (A/B/C), with Deal Score, Risk, and wealth/timeline highlights
    Scenarios come from Rental Property Calculator, Fix & Flip (Pro), BRRRR, Airbnb, and other Real Estate tools that save deals.
    Rent Pricing Intelligence
    Required rent for break-even, 8% or 10% cash-on-cash, and market risk
    Property & Financing
    Operating Expenses (annual $)
    Lease Profitability Simulator
    10-year projection with rent escalation and expense growth
    Vacancy Risk Calculator
    True vacancy cost and risk-adjusted return
    Property Expense Benchmark
    Compare your ratios: maintenance, CapEx, tax, insurance → Healthy / Risky / Overleveraged
    Portfolio Analyzer
    Aggregate 2–20 properties: total return, DSCR, leverage, net worth impact
    Properties (add up to 20)

    Enter at least 2 properties. Leave value/debt at 0 if unknown; portfolio return uses cash flow only.

    Cap Rate
    Capitalization rate: NOI ÷ purchase price
    Cash Flow
    Monthly income minus expenses and debt service
    Cash-on-Cash Return
    Annual cash flow ÷ total cash invested
    DSCR
    Debt service coverage ratio: NOI ÷ annual debt service
    House Flipping Profit
    Purchase, repair, sell price, and costs → profit and ROI
    Down Payment
    Purchase price and down % → down payment amount
    Closing Cost
    Estimate closing costs from purchase price or loan amount
    Price per Square Foot
    Price and square footage → $/sq ft (or enter $/sq ft to get price)
    Area & FAR
    Lot area, footprint, and floors → floor area ratio (FAR)
    Occupancy Load
    Area and load factor → maximum occupants
    Ramp Slope
    Rise and run → slope percent and ratio
    Sun Angle & Shadow
    Any two of height, sun angle, or shadow length → solve the third
    Enter any two values; the third will be calculated. Use consistent units for height and shadow.
    Concrete
    Slab length, width, and thickness → volume and bag count
    Tile
    Room size and tile size → tiles needed (with waste)
    Paint
    Room dimensions and coats → gallons of paint
    Flooring
    Room area and waste → total flooring needed
    Stair Design
    Total rise and run → number of steps and dimensions
    Square Footage
    Length and width → area in sq ft and sq m
    Gravel
    Area and depth → gravel volume and tons
    Mulch
    Beds area and depth → mulch cubic yards and bags
    Roofing
    Roof size and pitch → squares and bundles
    Roofing Material Optimizer
    Roof geometry, complexity, and productivity → shingles, underlayment, fasteners, and labor estimate
    Deck
    Deck size → area and board count (approximate)
    Framing Layout Optimizer
    Wall length, stud spacing, and openings → studs, waste, and cost estimate
    Slab Thickness & Reinforcement Estimator
    Uniform load, f′c, slab size → suggested thickness, deflection estimate, rebar spacing suggestion, and takeoff
    Design inputs
    Reinforcement
    Suggested thickness from span/depth; deflection from one-way strip. Confirm with project specs and codes.
    Concrete Pour Planner
    Slab, waste, trucks, reinforcement, cost, crew, and cure milestones in one view
    Structural Load
    Uniform floor/roof load, span, and spacing → line load, reactions, and max moment/shear (for checking against tables)
    Results are for simple spans with uniform load. Use official span tables or an engineer for final sizing.
    Beam Load & Deflection Engine
    Multiple support types, uniform and point loads, wood/steel/concrete, deflection limits (L/240–L/480), pass/fail, minimum beam size
    Footing & Soil Bearing Planner
    Total load, soil bearing, footing size, safety margin, and settlement estimate
    Earthwork / Cut & Fill
    Area and average cut/fill depths → volumes in cubic yards and net balance
    Thermal / HVAC Load
    Rule-of-thumb heating & cooling load from area, height, and insulation level
    Approximate “block load” only. For detailed HVAC design, use full Manual J / ASHRAE methods.
    Room BTU Calculator
    Single room dimensions and insulation → recommended heating & cooling BTU/hr
    CFM Calculator
    Room volume and target air changes per hour → required supply airflow (CFM)
    Air Changes Per Hour
    Measured airflow and room size → air changes per hour (ACH)
    SEER Savings Estimator
    Existing vs new SEER, usage, and rate → annual energy savings and simple payback
    Heat Load Engine (Manual J Simplified)
    Floor area, envelope, windows, and climate → estimated heating & cooling BTU/hr and equipment size (conceptual)
    Conceptual sizing only. For permit or code‑critical designs, use full Manual J or local engineering standards.
    Duct Sizing Planner
    Target airflow, length, and friction rate → suggested duct size, velocity, and static margin (conceptual)
    HVAC System Cost & ROI Simulator
    Existing vs upgrade system (cooling + heating) → annual cost, lifetime cost, and simple payback
    Existing system
    Upgrade scenario
    Refrigerant Line Sizing
    Tonnage, line length, and rise → equivalent length, capacity impact, and oil return risk (conceptual)
    HVAC Quote Builder
    Equipment, labor, overhead, and financing → customer price, margin, and monthly payment
    Costs
    Add‑ons & margin
    Financing
    Bill of Materials (BOM)
    Quick material list with extended costs and project total
    Labor Burden & Productivity
    Crew size, wage, burden, and productivity → daily and total labor cost and cost per unit
    Project Margin Simulator
    Material volatility, labor shifts, and delays → best/worst-case margins and break-even
    Schedule / Gantt Export
    Any number of tasks → sequential schedule, dates (optional), and CSV-friendly rows
    Tasks are treated sequentially. Copy the CSV-style output row into your scheduling or Gantt software.
    Construction Bid Comparison
    Compare any number of bids with schedule, material normalization, and risk‑weighted cost model
    Bid
    Bid
    Bid
    Tax Bracket
    Effective vs marginal federal tax rate with bracket breakdown (2026 brackets)
    Income Tax Calculator
    Estimate federal refund or amount owed (2026 brackets, standard deduction)
    Marriage Tax Calculator
    Compare federal tax: filing jointly vs as two singles (marriage bonus or penalty)
    Estate Tax Calculator
    Federal estate tax estimate: assets minus liabilities and exemption (2026 exemption)
    One Rep Max (1RM)
    Estimate 1RM from weight and reps (Epley formula)
    Formula: Epley: 1RM ≈ weight × (1 + reps/30)
    Target Heart Rate
    Age-based zones (e.g. 50–85% max)
    Water Intake
    Daily water recommendation by weight and activity
    Sleep Cycle
    Wake time → suggested bedtimes (90‑min cycles)
    Blood Alcohol (BAC)
    Weight, sex, drinks, time → rough BAC estimate
    Blood Pressure
    Systolic / diastolic → category based on ACC/AHA guidelines.
    A1c & Average Glucose
    Convert between A1c (%) and estimated average glucose (eAG).
    Cholesterol Ratios
    Total, HDL, LDL, triglycerides → common lipid ratios and rough interpretation.
    Dosage
    mg/kg, weight → dose (mg); optional unit
    Life Expectancy
    Very rough estimate of remaining years based on age, sex, smoking, and lifestyle (for fun only — not medical advice)
    Waist-to-Hip
    Waist / hip → ratio and category
    Waist-to-Height
    Waist / height → ratio and cardio‑metabolic risk band
    Finance

    Use these tools for everyday spending, borrowing, and planning. Everyday Money covers tips, tax, discounts, and fuel costs. Vehicles helps with car affordability, loans, lease vs buy, and EV costs. Borrowing & Loans handles home affordability, mortgages, HELOCs, rent vs buy, and debt payoff. Income & Budget covers paychecks, salary, taxes, and budgeting. Wealth & Investment includes net worth, ROI, inflation, bonds, and college cost. Search or pick a category below to start.

    Tools by category

    Business

    Use these tools for pricing, margins, and running the business. Sales & Pricing covers discounts, margin vs markup, unit price, break-even, price increase, revenue growth, ROI, investment return, and creator revenue. Quotes & Invoices helps you generate quotes and invoices. Loan Comparison lets you compare loan offers. Search or pick a category below to start.

    Tools by category

    Real Estate

    Use these tools for deal screening, analysis, and property management. Deal Screening & Offers covers deal finder, 70% rule, fix & flip, wholesaling, and investor mortgage. Analyze & Execute includes rental property, rehab estimator, BRRRR, and Airbnb. Compare & Exit helps with deal comparison and sell vs keep. Property Management Suite covers rent pricing, lease profitability, vacancy risk, expense benchmark, and portfolio analyzer. Financing links to loans and home affordability. Quick Metrics & Tools includes rent vs buy, cap rate, cash flow, cash-on-cash, DSCR, house flip, down payment, closing cost, and price per sq ft. Search or pick a category below to start.

    Tools by category

    Retirement & Financial Planning

    Use these tools to plan wealth, retirement, and debt payoff. Build wealth covers the Wealth Builder engine and 401(k) growth. Retirement planning includes Retirement Architect, decision optimizer, master planner, income planner, and withdrawal & longevity planner. Debt & Cash Flow uses the Debt Destroyer engine. Compare scenarios helps you compare strategies. Finance & Real Estate links to home affordability, loan, rent vs buy, and HELOC. ROI & Business opens the ROI & Business Analyzer. Search or pick a category below to start.

    Tools by category

    Wealth Builder
    How much will I have? Replaces: Investment calculator, Compound interest, Savings, CD, Future value.
    Starting point
    Horizon
    Growth style
    Advanced (inflation, tax, fees)
    Portfolio growth (principal vs growth)
    Growth vs contributions
    Portfolio value over time
    Milestones
    Retirement Architect
    When can I stop working? Replaces: Retirement calculator, FIRE, Pension estimator.
    Lifestyle target
    Current progress
    Safety nets
    Portfolio growth
    Income sources
    Withdrawal sustainability
    Debt Destroyer
    When am I debt-free? Replaces: Loan payoff, Credit card payoff, Debt snowball, Consolidation.
    Debts
    NameBalance ($)APR (%)Min. payment ($)
    Debt balance over time
    Interest vs principal
    ROI & Business Analyzer
    Is this investment worth it? Replaces: ROI, IRR, Payback period, Present value, Business calculator.
    Cost vs profit
    Value over time
    Benchmark
    Compare Strategies
    Invest vs pay debt, real estate vs stocks, or multiple retirement ages — side-by-side.
    Comparison type
    Extra $ each month
    Comparison
    Over time
    Tech Tools

    Use these tools for display, color, encoding, and dev utilities. Display & Viewport covers screen resolution, browser info, viewport size, PPI, aspect ratio, typography, and file size. Color Tools helps with color conversion, picker, palettes, gradients, and image-to-palette. Encode & Decode handles Base64, URL, HTML, and Unicode. QR & Barcode generates QR and barcode images. Network includes subnet calculator and bandwidth. AI & LLM offers token counter and AI cost estimator. All tools run in the browser. Search or pick a category below to start.

    Tools by category

    Screen Resolution Checker
    Your current display resolution and pixel density (read-only)
    Browser Info
    Detected browser, platform, and capabilities
    Viewport Size
    Current browser window size (updates on resize)
    Screen Size / PPI Calculator
    Compute PPI from resolution and diagonal, or size from PPI
    Aspect Ratio Calculator
    Width and height → simplified ratio, decimal, and common name. Or pick a ratio and one dimension to get the other.
    From target ratio
    File Size Calculator
    Estimate uncompressed image or video size from resolution, bit depth, and (for video) FPS and duration.
    Typography Converter
    Convert between px, pt, and em (16px base)
    Result
    —
    IP Subnet Calculator
    IPv4 & IPv6 subnet analysis — network, broadcast, host range, and binary breakdown
    Color Code Converter
    Paste any color format — get HEX, RGB, HSL, HSV, CMYK with copy and live preview
    Recent colors
    Palette
    Contrast (WCAG)
    Color Picker (Eyedropper)
    Pick a color from your screen using the browser eyedropper
    Color Palette Generator
    Generate full palettes from a base color or random: complementary, triadic, analogous, or monochromatic
    Preview:#3B82F6
    Gradient Generator
    Build linear or radial CSS gradients with color stops — copy CSS
    Image → Color Palette
    Upload an image to extract dominant colors (palette)
    Encoders & Decoders
    Encode and decode text instantly. All processing happens locally.
    QR Code Generator
    Enter text or URL to generate a QR code image
    Barcode Generator
    Generate Code 128 barcode from text or numbers
    Text Tools

    Use these tools to analyze, format, and transform text. Count & Analyze covers word and character counts, line count, reading time, and keyword density. Format & Case helps with case conversion, reverse text, trim and normalize spaces and line endings. Clean & Strip removes duplicates, empty lines, numbers, special chars, and HTML tags. Find & Replace replaces text and adds prefixes or suffixes. Sort & Lines sorts, reverses, and shuffles lines. Extract & Compare extracts emails, URLs, numbers, and compares two texts. Encode & Convert converts text to binary, ASCII, Unicode, emoji names, and Morse. URL & Slug creates and cleans URL-friendly slugs. All processing runs in the browser and stays private. Search or pick a category below to start.

    Tools by category

    Developer Tools

    Use these tools for data, IDs, web, security, and code. JSON formats, validates, diffs, and inspects JSON. Data Formats handles CSV, XML, YAML format, validation, and conversion. IDs & Generators generates UUIDs, Nano IDs, and random hex. Web & HTTP parses URLs, query strings, and headers and builds HTTP requests. Security offers password generator, hashes, checksums, HMAC, and JWT inspector. Regex tests regex and provides cheat sheet and common patterns. Time converts Unix timestamps and ISO 8601. Code diffs, beautifies, minifies, and escape/unescape. Conversion converts number bases and byte array ↔ string. Inspect parses Base64 images and data URIs. Reference lists HTTP status codes, MIME types, and ports. All tools run in the browser. Search or pick a category below to start.

    Tools by category

    History
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