Body mass index (BMI) compares your weight with your height. This calculator accepts kilograms and centimetres or pounds and inches, and shows your category and healthy weight range.
How the bmi calculator works
BMI = weight (kg) ÷ height (m)². For adults, the WHO categories are: under 18.5 underweight, 18.5 to 24.9 normal weight, 25 to 29.9 overweight, and 30 or above obese.
Example
A person who weighs 70 kg and is 170 cm tall has a BMI of 70 ÷ 1.7² = 24.2, which is in the normal range.
Frequently asked questions
Is BMI accurate for everyone?
No. BMI does not separate muscle from fat, so athletes and older adults can be misclassified. Use it as a screening tool only.
What is a healthy BMI?
For most adults, 18.5 to 24.9.
Can children use this calculator?
No. Children and teenagers are assessed with age and sex specific growth charts. Ask a doctor.
Please note: results are estimates for general information only and are not medical advice. Read our full disclaimer.