Free Online Calculators for Finance, Health, Math, Conversions & More

Free BMR calculator. Estimate your basal metabolic rate and daily calorie needs by activity level with three trusted formulas, in calories or kilojoules.

Health Calculators

Ideal Weight Calculator

Free ideal weight calculator. Find your ideal body weight from the Devine, Hamwi, Robinson and Miller formulas, plus the healthy BMI range for your height.

Health Calculators

Army Body Fat Calculator

Free Army body fat calculator. Estimate body fat with the Army tape-measure method and check your result against the Army standard for your age and sex.

Health Calculators

Lean Body Mass Calculator

Free lean body mass calculator (LBM) . Estimate lean mass, fat mass and body fat from weight and height with the Boer, James, Hume and Peters formulas.

Health Calculators

Healthy Weight Calculator

This calculator computes a healthy body weight range based on a person's height and is most accurate for adults aged 18 or older.

Free Online Calculators for Money, Health, Math and Everyday Conversions

CalculatorBooth is a collection of 153 free online calculators and converters. Every calculator is free to use, needs no sign-up, and works on a phone, a tablet and a computer. Many pages also explain the formula that is used, with a worked example, so you can see how the answer is found and not only the number.

Financial Calculators

Work out loan payments, mortgages, interest, savings growth, taxes and salary. These financial calculators help you to compare your options before you borrow, save or invest.

Health Calculators

Find your BMI, daily calorie needs, body fat, ideal weight, running pace and pregnancy dates. These health calculators give estimates for general information, and they are not medical advice.

Conversion Tools

Change units of length, weight, temperature, area, volume, time and data storage, and convert between currencies.

Other Utilities

Date and time tools, calculators for building and home projects, electronics, weather and other everyday jobs.

Math Calculators

Solve percentage, fraction, geometry and statistics problems quickly, and check your own work step by step.

Why Use CalculatorBooth

Free and private. There is no account and no payment, and most calculations are made in your own browser.
Clear results. Each calculator shows the main answer first, with the details under it.
Made for phones. The pages are fast, and the calculators are easy to use on a small screen.
Checked formulas. We test every calculator, and we want to know if you find an error.

Calculatorbooth's sole focus is to provide fast, comprehensive, convenient, free online calculators in a plethora of areas. Currently, we have a growing suite of calculators to help you "do the math" quickly in areas such as finance, fitness, health, math, conversions, and others, and we are still developing more. Our goal is to become the one-stop, go-to site for people who need to make quick calculations. Additionally, we believe the internet should be a source of free information. Therefore, all of our tools and services are completely free, with no registration required.

We coded and developed each calculator individually and put each one through strict, comprehensive testing. However, please inform us if you notice even the slightest error – your input is extremely valuable to us. While most calculators on Calculatorbooth are designed to be universally applicable for worldwide usage, some may be for specific regions or parameters.