BMI Calculator
Calculate Body Mass Index from height and weight.
A general guide for adults, not medical advice — BMI doesn't account for muscle mass, bone density or body composition.
How it works
- 1Enter your height and weight.
- 2See your BMI and weight category instantly.
About this tool
Enter your height and weight in either metric (cm, kg) or imperial (ft/in, lb) units to get your Body Mass Index and weight category instantly, using the standard adult BMI thresholds.
What do the BMI categories mean?
Under 18.5 is classed as underweight, 18.5–24.9 as normal weight, 25–29.9 as overweight, and 30 or above as obesity — the standard adult thresholds.
Is BMI an accurate measure of health?
It’s a general population-level guide, not a diagnosis — it doesn’t account for muscle mass, bone density or body composition, so athletes and very muscular people in particular can score higher than their actual body fat would suggest. This tool isn’t medical advice.
Is my data sent anywhere?
No, everything happens entirely in your browser.