About the bmi calculator
Body mass index compares weight with height and is widely used as a quick screening measure for adults. It doesn’t measure body fat directly and doesn’t account for muscle, age, sex, or ethnicity, so it is best read alongside other information by a healthcare professional.
How to use this calculator
- Enter your height (in inches or centimeters).
- Enter your weight.
- Read your BMI and category.
Worked examples
- 1.778 m, 69.9 kg
- 69.9 ÷ 1.778² = 22.1
BMI 22.1.
Measurement guidance
Accurate inputs
Measure height without shoes and weight at a consistent time of day.
Frequently asked questions
Is BMI accurate for athletes?
It can overestimate in muscular people because it doesn’t distinguish muscle from fat.
Can children use this?
No. Children and teens use BMI-for-age percentiles.
Is this medical advice?
No. Talk to a healthcare professional about your health.