About this calculator
BMI = weight (kg) ÷ height (m)². The World Health Organization’s adult categories are: under 18.5 underweight, 18.5–24.9 healthy weight, 25–29.9 overweight, and 30 or more obesity.
Worked example
70 kg ÷ (1.75 m × 1.75 m) = 22.9, in the healthy range. At 1.75 m, the healthy range is about 56.7 to 76.3 kg.
How to use the BMI calculator
- Enter the weight.
- Enter the height.
- Read the result — it updates as you type.
Frequently asked questions
What is a healthy BMI?
For most adults, 18.5 to 24.9.
Is BMI accurate for athletes?
Not always. BMI can’t tell muscle from fat, so very muscular people may score as overweight.