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Calculators
Free calculators for everyday money, health, math, scheduling, and business questions. Each page explains how the result is computed.
Loan Calculator
Estimate the monthly payment, total repayment, and total interest for a fixed-rate amortizing loan from principal, annual rate, and term in years.
Open calculator →FinanceMortgage Calculator
Estimate principal-and-interest payments and total interest for a fixed-rate home loan from purchase price, down payment, rate, and term.
Open calculator →FinanceAPR Calculator
Estimate an effective annual percentage rate when upfront loan fees reduce the cash you actually receive.
Open calculator →FinanceCompound Interest Calculator
Project compound growth with an initial principal, a fixed rate, and ordinary end-of-period contributions at a chosen compounding frequency.
Open calculator →FinanceSavings Calculator
Estimate a savings balance with monthly compounding and regular end-of-month deposits from a starting balance, deposit amount, rate, and years.
Open calculator →FinanceROI Calculator
Calculate net profit and simple return on investment, including optional additional costs.
Open calculator →FinanceRetirement Calculator
Project a retirement savings balance from current savings, monthly contributions, and an assumed return.
Open calculator →FinanceInvestment Growth Calculator
Project long-term investment growth with recurring contributions at a selected frequency.
Open calculator →FinanceDiscount Calculator
Calculate a discount, the reduced price, and optional tax applied after the discount.
Open calculator →FinanceVAT Calculator
Add VAT to a net amount or remove VAT from a tax-inclusive gross amount.
Open calculator →FinanceTip Calculator
Calculate a tip, total bill, and equal per-person split.
Open calculator →FinanceEmergency Fund Calculator
Estimate the emergency fund you need, your current coverage, and the monthly saving required to reach the goal.
Open calculator →FinanceSimple Interest Calculator
Calculate simple interest and the total amount owed or earned over a fixed term.
Open calculator →FinanceDebt Payoff Calculator
Estimate how long it takes to pay off a revolving balance with fixed monthly payments.
Open calculator →FinanceCredit Card Interest Calculator
Project how a credit-card balance grows when unpaid interest compounds monthly.
Open calculator →FinanceRefinance Calculator
Compare current and refinanced loan payments and estimate closing-cost break-even.
Open calculator →FinanceInflation Calculator
Estimate future cost and eroded purchasing power under a constant inflation rate.
Open calculator →FinanceNet Worth Calculator
Calculate net worth as total assets minus total liabilities.
Open calculator →FinancePaycheck Calculator
Estimate net pay after a flat tax rate and other deductions.
Open calculator →FinanceHourly to Salary Calculator
Convert an hourly wage into annual and monthly salary equivalents.
Open calculator →FinanceSalary to Hourly Calculator
Convert an annual salary into equivalent hourly and weekly pay.
Open calculator →FinanceOvertime Pay Calculator
Calculate regular pay, overtime pay, and total pay for a pay period.
Open calculator →FinancePresent Value Calculator
Discount a future lump sum to today's present value at a constant rate.
Open calculator →FinanceRule of 72 Calculator
Estimate years for an investment to double using the Rule of 72.
Open calculator →HealthBMI Calculator
Estimate adult body mass index from metric height and weight, then map the result to a standard adult screening category.
Open calculator →HealthBMR Calculator
Estimate resting daily energy expenditure with the Mifflin–St Jeor equation.
Open calculator →HealthTDEE Calculator
Estimate total daily energy expenditure from BMR and a selected activity factor.
Open calculator →HealthCalorie Deficit Calculator
Model a daily calorie adjustment from maintenance energy and a weekly weight-change target.
Open calculator →HealthBody Fat Calculator
Estimate body-fat percentage with the circumference-based US Navy method.
Open calculator →HealthWeight Reference Calculator
Compare four historical height-based weight-reference equations.
Open calculator →HealthWater Intake Calculator
Estimate daily fluid volume from body weight, activity time, and climate.
Open calculator →HealthProtein Intake Calculator
Estimate a broad daily protein range by body weight and activity goal.
Open calculator →HealthPregnancy Due Date Calculator
Estimate a pregnancy due date from the first day of the last menstrual period and usual cycle length.
Open calculator →HealthOvulation Calculator
Estimate ovulation, a fertile window, and the next period from cycle assumptions.
Open calculator →HealthMacro Calculator
Split daily calories into protein, carbohydrate, and fat gram targets from percentage shares.
Open calculator →HealthHeart Rate Zone Calculator
Estimate Karvonen training zones from age and resting heart rate.
Open calculator →HealthRunning Pace Calculator
Calculate pace per kilometer and average speed from distance and finish time.
Open calculator →HealthOne Rep Max Calculator
Estimate one-repetition maximum using Epley and Brzycki formulas.
Open calculator →HealthWaist Hip Ratio Calculator
Calculate waist-to-hip circumference ratio.
Open calculator →HealthLean Body Mass Calculator
Estimate lean body mass and fat mass from weight and body-fat percentage.
Open calculator →MathPercentage Calculator
Solve common percentage questions and percentage increases or decreases.
Open calculator →MathPercentage Change Calculator
Measure the absolute and percentage change between two values.
Open calculator →MathFraction Calculator
Add, subtract, multiply, or divide two integer fractions and simplify the result.
Open calculator →MathAverage Calculator
Summarize a comma-separated numeric list with its count, sum, mean, minimum, and maximum.
Open calculator →MathRatio Calculator
Simplify an integer ratio and calculate its finite decimal comparison.
Open calculator →MathGPA Calculator
Estimate a credit-weighted unweighted GPA on a 4.0 scale.
Open calculator →MathArea Calculator
Calculate area for rectangles, squares, triangles, circles, and trapezoids.
Open calculator →MathVolume Calculator
Calculate volume for cubes, rectangular prisms, cylinders, cones, and spheres.
Open calculator →MathSpeed Calculator
Solve for speed, distance, or time using metric or imperial travel units.
Open calculator →MathUnit Converter
Convert length, mass, temperature, area, and volume units with deterministic factors.
Open calculator →MathGrade Calculator
Convert a raw score into a percentage grade.
Open calculator →MathFinal Grade Calculator
Find the final-exam score needed to reach a desired course grade.
Open calculator →MathWeighted Grade Calculator
Average scores with explicit weights.
Open calculator →MathLCM Calculator
Find the least common multiple of two non-zero integers.
Open calculator →MathGCD Calculator
Find the greatest common divisor of two integers.
Open calculator →MathQuadratic Formula Calculator
Solve ax² + bx + c = 0 for real roots.
Open calculator →MathPythagorean Theorem Calculator
Solve for a right-triangle hypotenuse or missing leg.
Open calculator →MathPermutation Combination Calculator
Calculate permutations nPr or combinations nCr.
Open calculator →MathStandard Deviation Calculator
Compute mean plus population and sample standard deviation.
Open calculator →MathMedian Calculator
Find the median of a numeric list.
Open calculator →BusinessProfit Margin Calculator
Calculate profit and profit margin from revenue and total cost.
Open calculator →BusinessGross Margin Calculator
Calculate gross profit and gross margin before operating expenses.
Open calculator →BusinessNet Profit Calculator
Estimate net profit after product, operating, interest, and tax costs.
Open calculator →BusinessMarkup Calculator
Calculate markup amount and markup percentage from cost and selling price.
Open calculator →BusinessBreak-even Calculator
Estimate unit sales and revenue required to cover fixed and variable costs.
Open calculator →BusinessCommission Calculator
Calculate sales commission and total compensation including base pay.
Open calculator →BusinessSales Tax Calculator
Add a sales-tax percentage to a pre-tax price.
Open calculator →BusinessRevenue Growth Calculator
Measure absolute and percentage revenue growth between two periods.
Open calculator →BusinessInventory Turnover Calculator
Estimate inventory turnover and average days inventory is held.
Open calculator →BusinessDepreciation Calculator
Calculate straight-line depreciation, accumulated depreciation, and book value.
Open calculator →BusinessCash Flow Calculator
Calculate net cash flow from inflows and outflows.
Open calculator →BusinessOperating Margin Calculator
Measure operating margin from operating income and revenue.
Open calculator →BusinessCustomer Lifetime Value Calculator
Estimate simple customer lifetime value from spend and retention length.
Open calculator →BusinessChurn Rate Calculator
Calculate period churn rate from starting customers and customers lost.
Open calculator →BusinessPayback Period Calculator
Estimate years to recover an investment from constant annual cash inflows.
Open calculator →BusinessWorking Capital Calculator
Calculate working capital from current assets and current liabilities.
Open calculator →BusinessCurrent Ratio Calculator
Calculate the current ratio liquidity measure.
Open calculator →BusinessBurn Rate Calculator
Estimate monthly cash burn and runway from cash balances over time.
Open calculator →BusinessReading Time Calculator
Estimate reading time from word count and reading speed.
Open calculator →BusinessBillable Hours Calculator
Calculate billable amount from hourly rate and hours.
Open calculator →BusinessFreelance Rate Calculator
Back into a required freelance hourly rate from income and overhead goals.
Open calculator →BusinessCOGS Calculator
Calculate cost of goods sold from inventory and purchases.
Open calculator →Date & TimeAge Calculator
Calculate age on a specified date.
Open calculator →Date & TimeDate Difference Calculator
Find the signed and absolute difference between two dates.
Open calculator →Date & TimeBusiness Days Calculator
Count weekdays between two dates.
Open calculator →Date & TimeCountdown Calculator
Measure a date-based countdown from an explicit starting date.
Open calculator →Date & TimeTime Duration Calculator
Calculate elapsed wall-clock time between two times.
Open calculator →Date & TimeWork Hours Calculator
Calculate worked time after an unpaid break.
Open calculator →Date & TimeWeek Number Calculator
Find the ISO week number for a date.
Open calculator →Date & TimeDue Date Calculator
Add calendar or weekday-only days to a start date.
Open calculator →Date & TimeTime Zone Difference Calculator
Compare two explicit UTC offsets.
Open calculator →Date & TimeDays Until Calculator
Count signed calendar days until a target date.
Open calculator →Date & TimeAdd Days Calculator
Add or subtract a whole number of calendar days from a start date.
Open calculator →Date & TimeAdd Months Calculator
Add or subtract whole months while clamping end-of-month overflow.
Open calculator →Date & TimeWeekday Calculator
Find the weekday name and number for a calendar date.
Open calculator →Date & TimeWorking Days in Month Calculator
Count Monday–Friday weekdays in a calendar month.
Open calculator →Date & TimePayday Calculator
Project the next and Nth payday from a start date and pay-cycle length.
Open calculator →ConvertersLength Converter
Convert common metric, imperial, and US customary length units.
Open calculator →ConvertersMass Converter
Convert mass units, including kilograms, pounds, ounces, and tonnes.
Open calculator →ConvertersTemperature Converter
Convert Celsius, Fahrenheit, and Kelvin temperatures.
Open calculator →ConvertersArea Converter
Convert area units from square centimeters through square kilometers, acres, and hectares.
Open calculator →ConvertersVolume Converter
Convert metric, cubic, US liquid, and imperial volume units.
Open calculator →ConvertersPressure Converter
Convert pascals, bar, atmospheres, psi, and torr.
Open calculator →ConvertersSpeed Converter
Convert common road, scientific, aviation, and maritime speed units.
Open calculator →ConvertersData Size Converter
Convert decimal data-size units and IEC binary data-size units.
Open calculator →ConvertersEnergy Converter
Convert joules, food calories, watt-hours, and British thermal units.
Open calculator →ConvertersPower Converter
Convert watts, kilowatts, mechanical horsepower, and BTU per hour.
Open calculator →ConvertersAngle Converter
Convert degrees, radians, gradians, and turns.
Open calculator →ConvertersTime Unit Converter
Convert seconds, minutes, hours, days, and weeks.
Open calculator →ConvertersForce Converter
Convert newtons, kilonewtons, pound-force, and dynes.
Open calculator →ConvertersFrequency Converter
Convert hertz, kilohertz, megahertz, gigahertz, and RPM.
Open calculator →ConvertersFuel Economy Converter
Convert US MPG, L/100 km, and km/L fuel-economy figures.
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