Enter height and weight. The result updates as you type.
Not medical advice. Results are general estimates for adults and do not replace advice from a doctor or registered dietitian.
How to use it
BMI (body mass index) is weight in kilograms divided by height in metres squared. Choose metric or imperial units and enter your height and weight; imperial values are converted to kg and m first.
The World Health Organization groups adult BMI as: under 18.5 underweight, 18.5–24.9 healthy range, 25–29.9 overweight, 30 and above obesity (classes I–III from 30, 35 and 40). The page also shows the weight range that gives a BMI of 18.5–24.9 for your height.
BMI is a screening number. It does not separate muscle from fat, and it is not meant for children, pregnancy or very muscular people. Waist size, blood tests and a doctor’s view say more about health.
Frequently asked questions
What is a healthy BMI?
For adults, WHO defines 18.5 to 24.9 as the healthy range. Some health bodies use lower cut-offs for people of Asian descent.
Is BMI accurate for athletes?
Not very. Muscle is heavier than fat, so muscular people can have a high BMI without excess body fat.
Can children use this calculator?
No. Children and teenagers need age- and sex-specific BMI percentiles; ask a paediatrician.