BMI Calculator
Body mass index compares your weight with your height to give a quick picture of whether your weight is healthy. Enter your height and weight to see your category and the healthy weight range for your height.
Calculator
This result is an educational estimate, not a diagnosis. Ask your doctor to interpret it.
What does this mean?
Advice for you
How does this calculator work?
BMI is your weight in kilograms divided by the square of your height in metres. The categories follow the World Health Organization's adult classification:
- Below 18.5: underweight
- 18.5 – 24.9: healthy weight
- 25 – 29.9: overweight
- 30 – 34.9: obesity class I
- 35 and above: severe obesity
Measure your waist too: more than 94 cm for men or 80 cm for women points to excess belly fat, even with a normal BMI.
Scientific sources
- World Health Organization. A healthy lifestyle — WHO recommendations (BMI classification).
- NICE guideline NG246: Overweight and obesity management (2025).
Frequently asked questions
Is BMI accurate for everyone?
It is a good screening tool for most adults, but it cannot tell muscle from fat. It can read high in athletes and does not apply to pregnant women or children.
What is a normal BMI?
For adults, a healthy BMI is between 18.5 and 24.9 kg/m².
Is BMI different for men and women?
The formula and categories are the same for adult men and women, but fat distribution differs — so measuring your waist is useful too.
How much weight should I lose?
Losing 5 to 10% of your current weight brings clear health benefits, even if you don't reach the healthy range.