BMI Calculator
Body Mass Index from your height and weight, with the healthy range.
How this bmi calculator works
This free online bmi calculator takes the numbers you enter and applies a standard formula for this kind of calculation, showing the result instantly with no page reload. Body Mass Index from your height and weight, with the healthy range.
Everything runs client-side in JavaScript, so your inputs never leave your device — there's no server, no account and no tracking involved in getting your answer.
Frequently asked questions
For most adults, the World Health Organization defines 18.5–24.9 as the normal-weight range. Under 18.5 is considered underweight, 25–29.9 overweight, and 30+ obese.
BMI doesn't distinguish muscle from fat, so it can misclassify very muscular or very lean individuals. It's a useful screening tool, not a diagnosis — talk to a doctor for a full health picture.