Free Online Calculators
Fast, accurate, and ad-free calculators for math, finance, health, and everyday life. Real-time results, shareable URLs, and dark mode built in.
Math Calculators
Percentage Calculator
Calculate percentages 7 ways: find percent, find whole, percent change, percent difference, add/subtract percent, and reverse percent.
Fraction Calculator
Add, subtract, multiply, divide, compare, and solve fractions. Multi-fraction operations, solve for X, and step-by-step work.
Equivalent Fractions Calculator
Find equivalent fractions for any proper, improper, or mixed fraction. Shows the first 100 equivalent fractions.
Average Calculator
Calculate mean, median, mode, range, and standard deviation with step-by-step work. Includes weighted average mode.
Ratio Calculator
Simplify, solve proportions, scale, split, compare ratios, and generate equivalent ratio tables.
Exponent Calculator
Calculate powers, roots, exponentials, and logarithms. Solve xⁿ, ⁿ√x, eˣ, and log expressions.
Square Root Calculator
Calculate square roots, cube roots, and nth roots. Simplify radicals with prime factorization steps and Babylonian method walkthrough.
Quadratic Formula Calculator
Solve quadratic equations using the quadratic formula. Find real and complex roots, discriminant, vertex, and step-by-step solution.
Scientific Calculator
Full scientific calculator with trigonometry, logarithms, exponents, and memory functions.
LCM Calculator
Calculate the Least Common Multiple of two or more numbers. Shows prime factorization and GCD.
Long Division Calculator
Long division with step-by-step work shown. Get quotient, remainder, decimal, and mixed fraction.
Roman Numeral Converter
Convert between Roman numerals and Arabic numbers. Includes date converter with separator support.
Mean, Median, Mode, Range Calculator
Calculate mean, median, mode, range, and geometric mean. Includes column chart and sorted data display.
Density Calculator
Calculate density, mass, or volume using ρ = m/V. Supports multiple units with common material reference.
Molality Calculator
Calculate molality, solute mass, solvent mass, or molar mass. Solve b = n/W with unit conversions and common solute reference.
Mass Calculator
Calculate mass from density and volume (m = ρ × V). Supports multiple units with conversions and material presets.
Matrix Calculator
Perform matrix operations: addition, subtraction, multiplication, transpose, determinant, inverse, power, and scalar multiply.
Hex Calculator
Hex arithmetic and conversions between hexadecimal, decimal, binary, and octal.
Slope Calculator
Calculate slope, angle, distance, and line equation from two points or a point and slope. Includes visual graph.
Volume Calculator
Calculate volumes of 11 common 3D shapes with unit conversions between cubic feet, meters, liters, and gallons.
Permutation and Combination Calculator
Calculate permutations (nPr) and combinations (nCr) with factorial breakdown. Supports large numbers up to n=170.
Circumference to Diameter Calculator
Convert circumference to diameter, radius, and area. Enter any circle measurement and get all others instantly.
Finance Calculators
Pay Raise Calculator
Calculate your new pay after a raise. Supports percentage, flat amount, and new rate. See hourly, weekly, monthly, and yearly breakdowns.
Auto Loan Calculator
Calculate monthly car payments, total interest, and view amortization schedules. Factor in trade-in, down payment, taxes, and fees.
401(k) Calculator
Estimate your 401(k) balance at retirement, calculate early withdrawal costs, and optimize employer match contributions.
Simple Interest Calculator
Calculate simple interest on loans and investments. Solve for balance, principal, rate, or term with step-by-step work.
Compound Interest Calculator
Calculate compound interest with contribution timing toggle, cumulative breakdown, and year-by-year growth showing principal vs contributions vs interest.
APY Calculator
Calculate annual percentage yield from a nominal interest rate and compounding frequency. Optionally estimate future value and total interest.
Cap Rate Calculator
Calculate the capitalization rate for a rental property. Enter property value, gross income, and operating expenses to find cap rate and NOI.
Rule of 72 Calculator
Calculate the time or rate needed to double an investment using the Rule of 72. Shows both estimated and exact results.
Future Value Calculator
Calculate the future value of an investment with periodic deposits. See growth schedule with interest breakdown.
Amortization Calculator
Calculate loan amortization with extra payments, principal vs interest breakdown, and annual or monthly schedules.
Mortgage Calculator
Calculate monthly mortgage payments, total interest, and view amortization schedules for home loans.
Mortgage Payoff Calculator
Calculate how extra payments or biweekly payments accelerate mortgage payoff and save on interest.
Salary Calculator
Convert between salary, hourly, and monthly pay with overtime, 401(k), and health insurance deductions. See adjusted take-home across all periods.
Debt Payoff Calculator
Side-by-side avalanche vs snowball comparison showing interest saved and payoff timeline for each debt.
Loan Calculator
Calculate monthly loan payments with extra payment comparison showing interest and time saved. Includes donut chart and full amortization schedule.
Tax Bracket Calculator
Calculate 2025 federal income tax with FICA, optional deductions (401k, HSA, itemized), and total tax burden breakdown.
Take-Home Pay Calculator
Calculate your 2026 take-home pay after federal tax, FICA, state tax, and deductions. Includes OBBB tip and overtime exemptions.
Sales Tax Calculator
Calculate sales tax, reverse-calculate pre-tax prices, or find the tax rate. Includes 2026 US state rates.
Currency Calculator
Convert between 30+ currencies with live exchange rates. Includes custom rate converter and major currency cross-rate table.
Credit Card Payoff Calculator
See how long to pay off credit card debt. Compare minimum vs fixed payments, and analyze balance transfer savings.
Rent vs Buy Calculator
Compare renting vs buying with investment opportunity cost, PMI, HOA, equity tracking, and break-even year highlight.
Retirement Calculator
Plan your retirement with 4 calculation modes. See how much to save, withdraw, and how long savings last.
Rent Affordability Calculator
Calculate maximum affordable rent based on income, debts, and expenses. Uses the 40% gross income rule with customizable percentage slider and detailed budget breakdown.
HELOC Calculator
Calculate HELOC payments for draw and repayment periods. See total interest, amortization schedule, and compare costs.
Refinance Calculator
Compare your current mortgage with a refinanced loan. See monthly savings, break-even point, APR, and lifetime cost.
Roth IRA Calculator
Estimate Roth IRA balance at retirement and compare tax-free growth vs a taxable account.
Lease Calculator
Calculate lease monthly payment or find the effective interest rate. See depreciation, money factor, and payment schedule.
Boat Loan Calculator
Calculate boat loan monthly payments with down payment, trade-in, sales tax, and fees. See total cost and amortization schedule.
Debt Consolidation Calculator
Compare existing debts against a consolidation loan. See monthly payment, total interest, and time savings side by side.
Interest Rate Calculator
Multi-solve loan calculator: find rate, payment, principal, or term from any 3 values. Includes donut chart and amortization schedule.
ROI Calculator
Calculate return on investment (ROI) and annualized ROI. Compare investment profitability.
Savings Calculator
Calculate savings growth with compound interest, periodic contributions, annual increases, and tax impact.
VAT Calculator
Calculate VAT from any two values: rate, net price, gross price, or tax amount. Add or remove VAT instantly.
Health Calculators
Weight Loss Percentage Calculator
Calculate your weight loss percentage from initial and current weight. Shows total loss in pounds and kilograms.
BMI Calculator
Calculate BMI, BMI Prime, Ponderal Index, and Trefethen BMI. Visual gauge, weight targets, and Asian-adjusted thresholds.
Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method. Enter your measurements for an accurate assessment.
TDEE Calculator
Calculate TDEE with 3 BMR formulas, macro breakdown for cutting/bulking, body composition, and goal timeline.
Calorie Calculator
Calculate daily calorie needs using the Mifflin-St Jeor equation. Find calories for weight loss, maintenance, and gain.
Sleep Calculator
Calculate optimal bedtimes, wake times, and nap durations based on sleep cycles. Includes age-based sleep recommendations.
Running Pace Calculator
Calculate running pace with race time prediction (Riegel formula), training pace zones, and per-mile/km splits.
Macro Calculator
Calculate daily macros with built-in TDEE. Enter body stats or calories directly to get protein, carbs, and fat targets.
BAC Calculator
Estimate blood alcohol content based on drinks, weight, gender, and time elapsed.
Period Calculator
Track menstrual cycle and predict next period. Calculate fertile window and ovulation dates.
Pregnancy Calculator
Calculate pregnancy due date from LMP or conception. Track gestational age and milestones.
Conception Calculator
Estimate conception date from due date, last period, or ultrasound. Includes fertile window.
Bra Size Calculator
Calculate bra size from bust and band measurements. Convert between US, UK, EU, and Australian sizing.
Lean Body Mass Calculator
Calculate lean body mass using Boer, James, and Hume formulas. Estimate fat-free mass from height, weight, and body fat.
Body Surface Area Calculator
Calculate body surface area using 8 formulas: Du Bois, Mosteller, Haycock, and more. Used for drug dosing and clinical assessments.
Ideal Weight Calculator
Calculate ideal body weight using Robinson, Miller, Devine, and Hamwi formulas. Compare results with healthy BMI range.
BMR Calculator
Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation. See daily calorie needs for 6 activity levels.
Army Body Fat Calculator
Calculate body fat using the Army tape test method (AR 600-9). Check compliance with military body composition standards.
1RM Calculator
Calculate one rep max from weight and reps. Get percentage-based training recommendations.
GFR Calculator
Estimate glomerular filtration rate using CKD-EPI 2021, MDRD, and Cockcroft-Gault. Includes pediatric Schwartz formula.
Calories Burned Walking Calculator
Calculate calories burned walking based on pace, body weight, and duration. Uses MET values from the Compendium of Physical Activities.
Everyday Calculators
Age Calculator
Calculate your exact age in years, months, and days. Find the time between any two dates.
How Old Was I Calculator
Find out how old you were on any date. Calculate age in years, months, days, hours, minutes, and seconds.
Add Times Calculator
Add multiple time durations together in hours, minutes, and seconds. Get results in HH:MM:SS and decimal hours.
Time Until Calculator
Calculate the time remaining until a specific time and date. Live countdown in days, hours, minutes, and seconds.
End of School Countdown Calculator
Calculate the time remaining until a specific time and date. Live countdown in days, hours, minutes, and seconds.
Weeks Between Dates Calculator
Calculate the number of weeks between two dates. Also shows total days, months, weekdays, and weekend days.
Inch Fraction Calculator
Convert inch fractions to decimal, decimal to fractions, and inches to metric. Supports all standard precisions.
Years Ago Calculator
Calculate the exact date a specified number of years ago. Find the day of the week, weeks ago, and days ago.
Tip Calculator
Calculate tips with rounding options, pre-tax tipping, service charge support, and bill splitting. Compare pre-tax vs post-tax tip amounts.
GPA Calculator
Calculate your GPA on a 4.0 scale. Add courses with grades and credit hours for an accurate cumulative GPA.
Date Calculator
Calculate days between dates or add/subtract days with business day counting and US federal holiday exclusion.
Discount Calculator
Calculate sale prices, percent off savings, and reverse-calculate original prices from discounted amounts.
Hours Calculator
Calculate work hours, overtime, and pay from your time card. Track regular and OT hours.
Wind Chill Calculator
Calculate the wind chill "feels like" temperature using the NOAA formula. Includes frostbite risk estimates.
Time Calculator
Add, subtract, and calculate time in days, hours, minutes, and seconds. Includes time expression parser and date offset calculator.
Tire Size Calculator
Compare tire sizes side by side. See differences in diameter, width, sidewall, circumference, and speedometer impact.
Conversion Calculator
Convert between common units of length, temperature, area, volume, and weight.
IP Subnet Calculator
Calculate IPv4 and IPv6 subnet details including network address, broadcast, host range, and CIDR notation.
Time Card Calculator
Weekly or biweekly time card with daily/weekly overtime, break tracking, CSV export, and browser save.
Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law. Enter any 2 values to solve the other 2.
Time Zone Calculator
Convert times between time zones. Enter a date and time, select source and target zones, and see the result instantly.
Resistor Calculator
Calculate resistance from color codes (4/5 band), series and parallel combinations, and conductor resistance.
Electricity Calculator
Estimate electricity usage and cost for any appliance. Calculate daily, weekly, monthly, and annual energy costs.
Fuel Cost Calculator
Estimate fuel cost for a trip based on distance, fuel efficiency, and gas price.
Engine Horsepower Calculator
Estimate engine horsepower from quarter-mile elapsed time or trap speed. Two methods using vehicle weight and drag strip data.
Electric Vehicle Fuel Savings Calculator
Compare gas vs electric vehicle fuel costs. Estimate annual savings, cost per mile, and long-term fuel savings.
Cooking Calculators
Recipe Scaler
Scale recipes up or down for any number of servings. Get instant ingredient conversions.
Cooking Measurement Converter
Convert cooking measurements: cups, tablespoons, ounces, grams, and temperature.
Meat Cooking Time Calculator
Calculate cooking times by method (oven, grill, slow cook) with rest time and carryover temperature guidance.
Baking Ratio Calculator
Calculate ingredient weights using baker's percentages for bread, cake, cookies, and more.
Home Calculators
Acreage Calculator
Calculate land area in acres from length and width. Converts to sq ft, hectares, sq m, and more.
Square Yards Calculator
Calculate square yardage from length and width. Includes unit conversion and optional cost estimation for carpet and flooring.
Square Footage Calculator
Calculate square footage for rooms and spaces. Get paint and flooring estimates.
Paint Calculator
Calculate paint and primer needed with custom door/window dimensions, ceiling toggle, and cost estimates.
Flooring Calculator
Calculate flooring for multiple rooms with waste presets by pattern (straight/diagonal/herringbone) and box/carton calculator.
Concrete Calculator
Calculate concrete for slabs, footings, columns, and stairways with quantity multiplier and adjustable waste factor. Get cubic yards and bag counts.
Fence Calculator
Calculate fence materials with gate support: posts, rails, pickets, concrete bags, screws, and gate hardware by fence style.
Mulch Calculator
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
Calculate gravel, crushed stone, or pea gravel needed. Get cubic yards, tons, and cost estimates.
Tile Calculator
Calculate tiles needed for floors, walls, and surfaces. Account for grout gaps, box sizes, and costs.
BTU Calculator
Calculate BTU needed for AC and heating. Estimate AC size based on room size, insulation, climate, and more.
Voltage Drop Calculator
Calculate voltage drop for electrical wire runs. Check NEC compliance for copper and aluminum wiring.
Pool Volume Calculator
Calculate how many gallons of water your pool holds. Supports rectangular, circular, oval, and oblong shapes.
Education Calculators
Student Loan Calculator
Calculate student loan payments with extra payment comparison showing interest and time saved. Includes amortization schedule and 3 repayment plans.
College Cost Calculator
Calculate true cost of college after financial aid. Compare sticker price vs net price.
Test Grade Calculator
Calculate your test grade as a percentage, fraction, and letter grade from total questions and wrong answers.
Business Calculators
Profit Margin Calculator
Calculate gross, operating, and net profit margins with markup conversion table. Includes stock trading and forex margin calculators.
Break-Even Calculator
Calculate break-even point in units and revenue. Understand contribution margin and fixed costs.
YouTube Revenue Calculator
Estimate YouTube AdSense earnings based on views and niche. Understand CPM and RPM.
Why Use Our Calculators?
Our calculators are built for speed, accuracy, and ease of use. Every tool calculates results in real time as you type — no submit buttons, no page reloads. Each calculator shows the formula and step-by-step breakdown so you understand the math behind the answer.
Unlike other calculator sites, we don't clutter the page with ads or require signups. Share any calculation via URL — the link pre-fills your inputs and shows the result instantly. Works on desktop, tablet, and mobile with full keyboard accessibility and dark mode support.
All calculators are free, open, and built with modern web standards for sub-second page loads. Whether you need a quick percentage calculation, want to check your BMI, or are planning compound interest on your savings, we have the right tool.