209 free calculators that give you the answer, and the reasoning

Money, health, math and everyday problems. Each tool shows the formula it uses, runs entirely in your browser, and needs no account.

209 calculators
0 sign-ups needed
0 KB of your data stored

Most used calculators

See all 209 →
Mortgage Calculator Estimate a full monthly mortgage payment including principal, interest, prope… Loan Calculator Work out the monthly payment, total interest and payoff date for any fixed-ra… Auto Loan Calculator Price a car loan with sales tax, dealer fees, a trade-in and a down payment f… Compound Interest Calculator Watch compounding work: the balance, the interest earned, and how much differ… BMI Calculator Calculate Body Mass Index from height and weight, and see which WHO category … Calorie Calculator Work out daily calorie needs with the Mifflin-St Jeor equation, adjusted for … Scientific Calculator A full scientific calculator with trigonometry, logarithms, powers, roots, me… Percentage Calculator Every common percentage question in one place: percent of a number, percent c… Age Calculator Calculate exact age in years, months and days, plus total weeks, days, hours … GPA Calculator Calculate semester and cumulative GPA on a 4.0, 4.3 or 5.0 scale from letter … Square Footage Calculator Measure floor area in square feet, yards and metres, with material cost and w… Tip Calculator Split a bill and tip between any number of people, with 15/18/20% shown side …
75 tools

Financial Calculators

Mortgage, loan, interest, tax, retirement and investment calculators.

31 tools

Fitness & Health Calculators

BMI, calories, macros, body fat, pregnancy and fitness calculators.

44 tools

Math Calculators

Algebra, geometry, statistics, fractions and number theory calculators.

54 tools

Other Calculators

Date, time, construction, conversion, automotive and everyday calculators.

5 tools

Calculators for Your Site

Free embeddable calculator widgets for your own website.

Why these calculators are worth trusting

The formula is on the page

You can check our arithmetic against a textbook. Where a standard exists — Mifflin-St Jeor, CKD-EPI, the IRS Uniform Lifetime Table — we name it and follow it.

Nothing leaves your device

Calculations run in JavaScript in your browser. Your salary, your weight and your debts are never transmitted, logged or stored.

Fast on any connection

No frameworks, no web fonts, no tracking scripts. A tool page is a single CSS file and two small scripts, and it works on a phone on 3G.

From the blog

All articles →

Questions about this site

Are these calculators free?

Yes. Every calculator is free, needs no account, and has no usage limit. There are no paywalls and no premium tier.

Do you store the numbers I enter?

No. Calculations run in your browser with JavaScript. Your figures are never sent to our servers, which is also why results appear instantly as you type.

How do I know a result is correct?

Each calculator states the formula it uses on the page, so you can verify it against a textbook or a second source. Where a standard exists — Mifflin-St Jeor for calories, CKD-EPI for eGFR, the IRS Uniform Lifetime Table for RMDs — we name it and follow it.

Can I put one of these calculators on my own website?

Yes. The embeddable widgets section gives you a one-line iframe snippet for several of the most popular calculators, free for personal and commercial sites.