Free Online Calculators

13 calculators for math, finance, and health — free, fast, no sign-up.

All Calculators

Calculator

Fast, free arithmetic — add, subtract, multiply, divide. Keyboard supported.

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BMI Calculator

Calculate your Body Mass Index from height and weight. Supports metric and imperial units.

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Age Calculator

Find your exact age in years, months, and days, plus days until your next birthday.

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Compound Interest Calculator

Calculate investment growth, total interest earned, and final balance over time.

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Days Between Dates

Count exact days, weeks, and months between any two dates — past or future.

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GPA Calculator

Add courses, letter grades, and credit hours to calculate your GPA on a 4.0 scale.

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Loan Calculator

See your monthly payment, total payment, and total interest for any loan.

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Percentage Calculator

Find percentages, percentage of a number, and percentage change between two values.

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Salary Calculator

Convert hourly to annual salary or estimate take-home pay after taxes, any pay period.

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Tip Calculator

Calculate tip amount, total bill, and per-person split for any group size.

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Mortgage Calculator

Calculate monthly payment, total interest, and full amortization schedule for any home loan.

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Retirement Calculator

Project your retirement savings with compound growth, inflation adjustment, and year-by-year chart.

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Debt Payoff Calculator

See how long to pay off debt or what monthly payment hits your target date. Full schedule included.

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Pick the calculator by what you're working out

These thirteen calculators each answer one question precisely, so the fastest way to choose is to start from the number you need rather than the tool's name. The groupings below sort them by the kind of problem they solve.

Money and finance

Borrowing or planning a large purchase? The loan calculator and mortgage calculator turn an amount, rate, and term into a monthly payment, while the compound interest and retirement tools project growth over time. For day-to-day money, reach for the salary, tip, and debt payoff calculators.

Health and everyday math

Use the BMI calculator for a quick body-weight check, and the percentage, GPA, age, and days-between-dates tools for the small calculations that come up constantly. When you just need arithmetic, the plain calculator covers it.