Is this BMI calculator free?

Yes, completely free with no account required. All calculations run in your browser with no data sent to any server.

Does my data leave my device?

No. BMI is computed entirely in JavaScript in your browser. No weight or height data is ever uploaded or stored.

Does it work on mobile?

Yes. The tool is mobile-first and works in Safari and Chrome on iOS and Android.

What BMI is considered healthy?

For adults, a BMI of 18.5–24.9 is considered normal weight. Under 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese. These ranges apply to most adults but may differ for athletes, elderly people, and certain ethnic groups.

BMI Calculator

Calculate your Body Mass Index (BMI) using metric (kg/cm) or imperial (lb/ft/in) units. See your weight category on a color-coded scale — 100% client-side.

Weight (kg) Height (cm)

About BMI

Body Mass Index (BMI) is weight in kilograms divided by height in metres squared (kg/m²). It is a widely used screening indicator but does not account for muscle mass, bone density, age, or fat distribution. Always consult a healthcare professional for personalised advice.

Formula: BMI = weight (kg) ÷ height (m)². Imperial: BMI = (weight (lb) ÷ height (in)²) × 703.

How to use

Select Metric (kg/cm) or Imperial (lb/ft/in) using the tabs at the top.
Enter your weight and height in the input fields.
Your BMI score and category appear instantly below the inputs.

Related calculators

TDEE Calculator — find your daily calorie maintenance needs
Age Calculator — calculate your exact age in years, months, and days
Weight Converter — convert kg, lb, stones, and more

BMI for specific groups

BMI Calculator for Women — BMI and healthy range context for women
BMI Calculator for Men — how muscle mass affects BMI for men

Frequently Asked Questions

Is this BMI calculator free?: Yes, completely free with no account required. All calculations run in your browser with no data sent to any server.
Does my data leave my device?: No. BMI is computed entirely in JavaScript in your browser. No weight or height data is ever uploaded or stored.
Does it work on mobile?: Yes. The tool is mobile-first and works in Safari and Chrome on iOS and Android.
What BMI is considered healthy?: For adults, a BMI of 18.5–24.9 is considered normal weight. Under 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese. These ranges apply to most adults but may differ for athletes, elderly people, and certain ethnic groups.

Last updated: 2026-05-20 By jarvisbox