Trusted, formula-transparent calculators
The calculator you can
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126 fast, ad-light online calculators for math, finance, health, and everyday life — each one shows the formula and step-by-step working behind the answer.
Math
22 tools Percentage Calculator — 7 Modes, Step-by-Step Work Calculate percentages 7 ways: find percent, find whole, percent change, percent difference, add/subtract percent, and reverse percent. Fraction Calculator — Step-by-Step Solver Add, subtract, multiply, divide, compare, and solve fractions with full step-by-step work. Chain up to 9 fractions, mixed numbers, simplify, and decimal conversions. Equivalent Fractions Calculator — First 100 Results Find equivalent fractions for any proper, improper, or mixed fraction. Shows the first 100 equivalent fractions instantly. Average Calculator — Mean, Median, Mode, Range, SD Calculate mean (sum divided by count), median, mode, range, and standard deviation with step-by-step work. Includes weighted average mode and a full statistics measures reference. Ratio Calculator — Simplify, Solve, Scale, Compare Simplify ratios, solve proportions, scale, split, compare, and generate equivalent ratio tables — all in one tool. Exponent Calculator — Powers, Roots, Logs, e^x Calculate powers, roots, exponentials, and logarithms. Solve xⁿ, ⁿ√x, eˣ, and log expressions with full work shown. Square Root Calculator — Simplify Radicals + Steps Calculate square roots, cube roots, and nth roots. Simplify radicals with prime factorization steps and the Babylonian method walkthrough. Quadratic Formula Calculator — Roots, Discriminant Solve quadratic equations using the quadratic formula. Find real and complex roots, discriminant, vertex, and full step-by-step solution. Scientific Calculator — Trig, Log, Exponents, Memory Full scientific calculator with trigonometry, logarithms, exponents, parentheses, and memory functions. Works on mobile and desktop. LCM Calculator — Least Common Multiple + Prime Steps Find the Least Common Multiple of two or more numbers. Shows prime factorization, GCD, and full step-by-step work. Long Division Calculator — Show Work Step-by-Step Long division with full step-by-step work shown. Get quotient, remainder, decimal, and mixed fraction results.
Roman Numeral Converter — Numbers, Dates Both Ways Convert between Roman numerals and Arabic numbers. Includes a date converter with separator support for full date strings. Mean, Median, Mode, Range Calculator — With Chart Calculate mean, median, mode, range, and geometric mean. Includes column chart visualization and sorted data display. Density Calculator — ρ = m/V, All Units, Materials Calculate density, mass, or volume using ρ = m/V. Supports multiple units with common material reference values. Molality Calculator — b = n/W, Solve Any Variable Calculate molality, solute mass, solvent mass, or molar mass. Solve b = n/W with unit conversions and a common solute reference. Mass Calculator — m = ρ × V, Density to Mass Calculate mass from density and volume (m = ρ × V). Supports multiple units with conversions and material presets. Matrix Calculator — Multiply, Inverse, Determinant Perform matrix operations: addition, subtraction, multiplication, transpose, determinant, inverse, power, and scalar multiply. Hex Calculator — Add, Subtract, Convert Hex/Dec/Bin Hex arithmetic and conversions between hexadecimal, decimal, binary, and octal. Includes bitwise operations. Slope Calculator — Two Points, Angle, Line Equation Calculate slope m = (y2 − y1) / (x2 − x1), angle, distance, and line equation from two points or a point and slope. Includes a grade, angle, and ratio conversion table and visual graph. Volume Calculator — 11 Shapes, ft³, m³, L, Gallons Calculate volumes of 11 common 3D shapes with unit conversions between cubic feet, cubic meters, liters, and gallons. Permutation & Combination Calculator — nPr, nCr Calculate permutations (nPr) and combinations (nCr) with factorial breakdown. Supports large numbers up to n=170. Circumference to Diameter — All Circle Values Convert circumference to diameter, radius, and area. Enter any circle measurement and get all others instantly.
Finance
33 tools Pay Raise Calculator — % or Flat, Hourly to Yearly Calculate your new pay after a raise — percentage, flat amount, or new rate. See hourly, weekly, monthly, and yearly breakdowns. Auto Loan Calculator — Trade-In, Tax, Amortization Calculate monthly car payments, total interest, and view amortization schedules. Factor in trade-in, down payment, taxes, and fees. 401(k) Calculator — Retirement, Match, Withdrawal Estimate your 401(k) balance at retirement, calculate early withdrawal costs, and optimize employer match contributions. Simple Interest Calculator — Solve I = Prt Any Way Calculate simple interest on loans and investments. Solve for balance, principal, rate, or term with step-by-step work. Compound Interest Calculator — Daily, Monthly, Yearly Calculate compound interest with contribution timing, cumulative breakdown, and year-by-year growth showing principal vs contributions vs interest. APY Calculator — Annual Yield from Nominal Rate Calculate annual percentage yield from a nominal interest rate and compounding frequency. Estimate future value and total interest. Cap Rate Calculator — Rental Property NOI & Yield Calculate cap rate from NOI and property value, or reverse it to find a property's value at a target cap rate. Free real estate calculator with NOI breakdown. Rule of 72 Calculator — Time to Double Investment Calculate the time or rate needed to double an investment using the Rule of 72. Shows both estimated and exact results. Future Value Calculator — FV with Periodic Deposits Calculate the future value of an investment with periodic deposits. See growth schedule with full interest breakdown. Amortization Calculator — Schedule + Extra Payments Calculate loan amortization with extra payments, principal vs interest breakdown, and annual or monthly schedules. Mortgage Calculator — Payment, Interest, Amortization Calculate monthly mortgage payments, total interest, and view amortization schedules for home loans. Mortgage Payoff Calculator — Biweekly + Extra Payments Calculate how extra payments or biweekly payments accelerate mortgage payoff and save on interest. Salary Calculator — Hourly to Yearly, Take-Home Pay Convert between salary, hourly, and monthly pay with overtime, 401(k), and health insurance deductions. See take-home across all periods. Debt Payoff Calculator — Avalanche vs Snowball Side-by-side avalanche vs snowball comparison showing interest saved and payoff timeline for each debt strategy. Loan Calculator — Payment, Extra Payment, Schedule Calculate monthly loan payments with extra payment comparison showing interest and time saved. Includes donut chart and amortization schedule. Tax Bracket Calculator 2025 — Federal + FICA + Deductions Calculate 2025 federal income tax with FICA, optional deductions (401k, HSA, itemized), and total tax burden breakdown. Take-Home Pay Calculator 2026 — Net Pay After Tax Calculate your 2026 take-home pay after federal tax, FICA, state tax, and deductions. Includes OBBB tip and overtime exemptions.
Sales Tax Calculator — Add, Reverse, By State Calculate sales tax, reverse-calculate pre-tax prices, or find the tax rate. Includes 2026 US state rates. Currency Calculator — 30+ Currencies, Live Rates Convert between 30+ currencies with live exchange rates. Includes custom rate converter and major currency cross-rate table. Credit Card Payoff Calculator — Min Payment Trap See how long to pay off credit card debt. Compare minimum vs fixed payments, and analyze balance transfer savings. Rent vs Buy Calculator — Break-Even + Investment Cost Compare renting vs buying with investment opportunity cost, PMI, HOA, equity tracking, and break-even year highlight. Retirement Calculator — How Much to Save & Withdraw Plan your retirement with 4 calculation modes. See how much to save, withdraw, and how long savings last. Rent Affordability Calculator — 30% & 40% Rules Calculate maximum affordable rent based on income, debts, and expenses. Uses the 30/40% income rules with budget breakdown. HELOC Calculator — Draw + Repayment Period Payments Calculate HELOC payments for draw and repayment periods. See total interest, amortization schedule, and compare costs. Refinance Calculator — Break-Even + Lifetime Cost Compare your current mortgage with a refinanced loan. See monthly savings, break-even point, APR, and lifetime cost. Roth IRA Calculator — Tax-Free Growth vs Taxable Estimate Roth IRA balance at retirement and compare tax-free growth vs a taxable brokerage account. Lease Calculator — Monthly Payment & Money Factor Calculate lease monthly payment or find the effective interest rate. See depreciation, money factor, and payment schedule. Boat Loan Calculator — Payment, Tax, Amortization Calculate boat loan monthly payments with down payment, trade-in, sales tax, and fees. See total cost and amortization schedule. Debt Consolidation Calculator — Side-by-Side Compare Compare existing debts against a consolidation loan. See monthly payment, total interest, and time savings side by side. Interest Rate Calculator — Solve Rate, Payment, Term Multi-solve loan calculator: find rate, payment, principal, or term from any 3 values. Includes donut chart and amortization schedule. ROI Calculator — Return on Investment + Annualized Calculate return on investment (ROI) and annualized ROI. Compare investment profitability over any time period. Savings Calculator — Compound Growth + Contributions Calculate savings growth with compound interest, periodic contributions, annual increases, and tax impact. VAT Calculator — Add, Remove, Find Rate from 2 Values Calculate VAT from any two values: rate, net price, gross price, or tax amount. Add or remove VAT instantly.
Health
21 tools Weight Loss Percentage Calculator — Track Loss kg/lb Calculate your weight loss percentage from initial and current weight. Shows total loss in pounds and kilograms. BMI Calculator — Asian Thresholds, Prime, Trefethen Calculate BMI, BMI Prime, Ponderal Index, and Trefethen BMI. Visual gauge, weight targets, and Asian-adjusted thresholds. Body Fat Calculator — U.S. Navy Tape Method Estimate your body fat percentage using the U.S. Navy method. Enter your measurements for an accurate body composition assessment. TDEE Calculator — Maintenance Calories + Macros Find maintenance calories with 3 BMR formulas plus macros for cutting or bulking. Most adults: 1,800–2,800 cal/day. Includes goal timeline. Calorie Calculator — Mifflin-St Jeor Daily Needs Calculate daily calorie needs using the Mifflin-St Jeor equation. Find calories for weight loss, maintenance, and gain. Sleep Calculator — Bedtime, Wake Time, Nap Cycles Calculate optimal bedtimes, wake times, and nap durations based on sleep cycles. Includes age-based sleep recommendations. Running Pace Calculator — Race Predictor + Splits Calculate running pace (time divided by distance) with race time prediction, training pace zones, per-mile and per-km splits, and a pace-to-finish-time chart for 5K, 10K, half, and marathon. Macro Calculator — Protein, Carbs, Fat from TDEE Calculate daily macros with built-in TDEE. Enter body stats or calories directly to get protein, carbs, and fat targets. BAC Calculator — Blood Alcohol from Drinks & Weight Estimate blood alcohol content based on drinks, weight, gender, and time elapsed. Educational use only. Period Calculator — Cycle, Ovulation, Fertile Window Track menstrual cycle and predict next period. Calculate fertile window and ovulation dates for the next 6 months. Pregnancy Calculator — Due Date from LMP or Conception Calculate pregnancy due date from LMP or conception. Track gestational age, trimesters, and milestones.
Conception Calculator — Estimate from Due Date or LMP Estimate conception date from due date, last period, or ultrasound. Includes the fertile window and full timeline. Bra Size Calculator — US, UK, EU, Australian Sizing Calculate bra size from bust and band measurements. Convert between US, UK, EU, and Australian sizing standards. Lean Body Mass Calculator — Boer, James, Hume Calculate lean body mass using Boer, James, and Hume formulas. Estimate fat-free mass from height, weight, and body fat. Body Surface Area Calculator — 8 Clinical Formulas Calculate body surface area using 8 formulas: Du Bois, Mosteller, Haycock, and more. Used for drug dosing and clinical assessments. Ideal Weight Calculator — 4 Formulas + Healthy BMI Calculate ideal body weight using Robinson, Miller, Devine, and Hamwi formulas. Compare results with healthy BMI range. BMR Calculator — Basal Metabolic Rate (Mifflin-St Jeor) Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation. See daily calorie needs for 6 activity levels. Army Body Fat Calculator — AR 600-9 Tape Test Calculate body fat using the Army tape test method (AR 600-9). Check compliance with military body composition standards. 1RM Calculator — One Rep Max + Training % Table Calculate one rep max from weight and reps. Get percentage-based training recommendations across 5 formulas. GFR Calculator — CKD-EPI 2021, MDRD, Cockcroft-Gault Estimate glomerular filtration rate using CKD-EPI 2021, MDRD, and Cockcroft-Gault. Includes pediatric Schwartz formula. Calories Burned Walking — Pace, Weight, MET-Based Calculate calories burned walking based on pace, body weight, and duration. Uses MET values from the Compendium of Physical Activities.
Everyday
26 tools Age Calculator — Years, Months, Days, Hours Exactly Calculate your exact age in years, months, and days from your date of birth. See age in weeks, hours, and total days, plus a reference table of common ages in every unit. How Old Was I Calculator — Age on Any Past Date Find out how old you were on any date. Calculate age in years, months, days, hours, minutes, and seconds. Add Times Calculator — Sum HH:MM:SS Durations Add multiple time durations together in hours, minutes, and seconds. Get results in HH:MM:SS and decimal hours. Time Until Calculator — Live Countdown to Any Date Calculate the time remaining until a specific time and date. Live countdown in days, hours, minutes, and seconds. End of School Countdown — Live Days, Hours, Minutes Live countdown to the end of the school year showing remaining school days (weekdays) and calendar days in real time, plus a weeks-to-school-days reference and dismissal-time mode. Weeks Between Dates Calculator — Plus Days & Months Calculate the number of weeks between two dates. Also shows total days, months, weekdays, and weekend days. Inch Fraction Calculator — Decimal, Fraction, mm Convert inch fractions to decimal, decimal to fractions, and inches to metric. Supports all standard precisions. Years Ago Calculator — Exact Date X Years Back Calculate the exact date a specified number of years ago from any start date. Find the day of the week, weeks ago, and days ago, with full leap-year accuracy. Tip Calculator — Compare %, Split Bill, Pre-Tax Mode Calculate tips (bill times percentage) with rounding options, pre-tax tipping, service charge support, and bill splitting. Includes a 15%, 18%, and 20% tip reference table. GPA Calculator — 4.0 Scale, Cumulative, by Credit Calculate your GPA on a 4.0 scale. Add courses with grades and credit hours for an accurate cumulative GPA. Date Calculator — Days Between, Add, Business Days Calculate days between dates or add/subtract days with business day counting and US federal holiday exclusion. Discount Calculator — Sale Price, % Off, Reverse Calculate sale prices, percent off savings, and reverse-calculate original prices from discounted amounts. Hours Calculator — Time Card, Overtime, Pay Calculate work hours, overtime, and pay from your time card. Track regular and OT hours with easy daily entry.
Wind Chill Calculator — NOAA Formula + Frostbite Calculate the wind chill "feels like" temperature using the NOAA formula. Includes frostbite risk estimates. Time Calculator — Add, Subtract, Duration, Date Offset Add, subtract, and calculate time in days, hours, minutes, and seconds. Includes time expression parser and date offset calculator. Tire Size Calculator — Compare Diameter, Speedometer Compare tire sizes side by side. See differences in diameter, width, sidewall, circumference, and speedometer impact. Unit Conversion Calculator — Length, Weight, Volume, ° Convert between common units of length, temperature, area, volume, and weight in one tool. IP Subnet Calculator — IPv4, IPv6, CIDR, Broadcast Calculate IPv4 and IPv6 subnet details including network address, broadcast, host range, and CIDR notation. Time Card Calculator — Weekly, Biweekly, OT, CSV Weekly or biweekly time card with daily/weekly overtime, break tracking, CSV export, and browser save. Ohm's Law Calculator — Volts, Amps, Ohms, Watts Calculate voltage, current, resistance, and power using Ohm's Law. Enter any 2 values to solve the other 2. Time Zone Calculator — Convert Between Any 2 Zones Convert times between time zones. Enter a date and time, select source and target zones, and see the result instantly. Resistor Calculator — Color Code, Series, Parallel Calculate resistance from color codes (4/5 band), series and parallel combinations, and conductor resistance. Electricity Calculator — kWh Cost per Appliance Estimate electricity usage and cost for any appliance. Calculate daily, weekly, monthly, and annual energy costs. Fuel Cost Calculator — Trip Gas Cost by MPG & Price Estimate fuel cost for a trip based on distance, fuel efficiency, and gas price. Horsepower Calculator — Torque, HP↔kW, Quarter Mile Calculate HP from torque × RPM ÷ 5252, convert between HP, kW, PS, and watts, or estimate engine HP from quarter-mile time and trap speed. EV Fuel Savings Calculator — Gas vs Electric Annual Compare gas vs electric vehicle fuel costs. Estimate annual savings, cost per mile, and long-term fuel savings.
Cooking
4 tools Recipe Scaler — Convert Servings + Ingredient Math Scale recipes up or down for any number of servings. Get instant ingredient conversions with imperial and metric units. Cooking Conversion Calculator — Cups, Tbsp, g, °F/°C Convert cooking measurements: cups, tablespoons, ounces, grams, and oven temperature between °F and °C. Meat Cooking Time Calculator — Roast, Grill, Slow Calculate cooking times by method (oven, grill, slow cook) with rest time and carryover guidance. Includes a per-pound roasting chart and USDA safe internal temperatures for beef, pork, chicken, turkey, and lamb. Baking Ratio Calculator — Baker's % for Bread, Cake Calculate ingredient weights using baker's percentages for bread, cake, cookies, and more.
Home
13 tools Acreage Calculator — Land Area in Acres, Hectares Calculate land area in acres from length and width. Converts to sq ft, hectares, sq m, and more. Square Yards Calculator — Carpet, Flooring, Cost Calculate square yardage from length and width. Includes unit conversion and optional cost estimation for carpet and flooring. Square Footage Calculator — Room Area + Paint Estimate Calculate square footage for rooms and spaces. Get paint and flooring estimates from one entry. Paint Calculator — Coats, Doors, Windows, Cost Calculate paint and primer needed with custom door/window dimensions, ceiling toggle, and cost estimates. Flooring Calculator — Multi-Room with Pattern Waste Calculate flooring for multiple rooms with waste presets by pattern (straight/diagonal/herringbone) and box/carton calculator. Concrete Calculator — Slabs, Footings, Columns, Bags Calculate concrete for slabs, footings, columns, and stairways with quantity multiplier and adjustable waste factor. Get cubic yards and bag counts. Fence Calculator — Posts, Pickets, Rails, Gates Calculate fence materials with gate support: posts, rails, pickets, concrete bags, screws, and gate hardware by fence style.
Mulch Calculator — Bagged vs Bulk, 8 Materials Calculate mulch, gravel, or stone for rectangle, circle, or triangle beds. Compare bagged vs bulk cost with 8 material types and overage slider. Gravel Calculator — Cubic Yards, Tons, Driveway Calculate gravel, crushed stone, or pea gravel needed. Get cubic yards, tons, and cost estimates. Tile Calculator — Floor or Wall Coverage with Grout Calculate tiles needed for floors, walls, and surfaces. Account for grout gaps, box sizes, and total cost. BTU Calculator — AC and Heating Size by Room Calculate BTU needed for AC and heating. Estimate AC size based on room size, insulation, climate, and more. Voltage Drop Calculator — NEC Wire Sizing Calculate voltage drop for electrical wire runs. Check NEC compliance for copper and aluminum wiring. Pool Volume Calculator — Gallons by Pool Shape Calculate how many gallons of water your pool holds. Supports rectangular, circular, oval, and oblong shapes.
Education
3 tools Student Loan Calculator — Repayment Plans + Schedule Calculate student loan payments with extra payment comparison showing interest and time saved. Includes amortization schedule and 3 repayment plans. College Cost Calculator — Net Price After Aid Calculate the true cost of college after financial aid. Compare sticker price vs net price across schools. Test Grade Calculator — % Score + Letter Grade Calculate your test grade as a percentage, fraction, and letter grade from total questions and wrong answers.
Business
4 tools Profit Margin Calculator — Gross, Net, Op + Markup Calculate gross, operating, and net profit margins with markup conversion table. Includes stock trading and forex margin calculators. Break-Even Calculator — Units, Revenue, Margin Calculate break-even point in units and revenue. Understand contribution margin and fixed cost coverage. YouTube Revenue Calculator — AdSense by Niche, Views Estimate YouTube AdSense earnings based on views and niche. Understand CPM and RPM differences. CTR Calculator — Click-Through Rate, CPC, CPM Calculate click-through rate, expected clicks, required impressions, and CPC/CPM for ads, search, email, and social campaigns.