BMI Calculator

BMI Calculator — Check Your Body Mass Index Online

Our BMI calculator computes your Body Mass Index from your height and weight in seconds — and shows which category you fall into plus your healthy weight range. Free, private, no signup.

What Is BMI & How to Calculate It?

BMI (Body Mass Index) is a simple screening measure: weight in kilograms divided by height in meters squared. To calculate BMI manually: BMI = kg / m². Standard categories are: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, and 30+ obesity. Our tool does the math and places you instantly.

Is BMI Accurate?

BMI is a useful population-level screening tool, but it does not measure body fat directly. Very muscular people, athletes, pregnant women, and the elderly can get misleading results — muscle weighs more than fat. Treat your result as a starting point for a conversation with a healthcare professional, not a diagnosis.

Frequently Asked Questions

What is a healthy BMI?

18.5 to 24.9 is the widely accepted healthy range for adults.

How do I calculate BMI without a calculator?

Divide your weight in kg by your height in meters squared. Example: 70 kg ÷ (1.75 × 1.75) = 22.9. Or just use the tool above — it is faster.

Does BMI differ for men and women?

The formula is the same, though healthy body-fat percentages differ by sex and age. The calculator shows the standard adult categories used worldwide.

For information only — not medical advice. Please consult a qualified healthcare professional for health decisions.