BMI calculator
Enter your weight and height to calculate your body mass index (BMI) and see which WHO category it falls into. For adults aged 18 and over.
How it works
BMI = weight (kg) ÷ height (m)². In imperial units the calculator first converts pounds to kilograms and feet and inches to meters.
WHO adult categories: below 18.5 underweight, 18.5–24.9 healthy weight, 25–29.9 overweight, 30 or more obesity. BMI is a screening measure that does not account for muscle mass, age or sex; ask a health professional for an assessment.
Frequently asked questions
What is a healthy BMI?
For most adults, a BMI from 18.5 to 24.9 is considered a healthy weight by the World Health Organization.
Is BMI accurate for athletes?
Not always. Muscle is denser than fat, so muscular people can have a high BMI without excess body fat.