What it does
The BMI Calculator works out your body mass index from your height and weight, in metric or imperial units. It shows which adult category the result falls in, the healthy weight range for your height, and how far you are from it.
How to use it
- Choose Metric (cm, kg) or Imperial (ft, in, lb).
- Enter your height and weight.
- Read your BMI, the category, the healthy weight range and the table of categories for your height.
The formula
BMI = weight in kg ÷ (height in m)². For imperial units the calculator converts to metric first.
Example
Someone 175 cm tall weighing 72 kg has a BMI of 23.5, which is in the healthy range. For that height, a healthy BMI of 18.5–24.9 is about 57–76 kg.
| Category | BMI |
|---|---|
| Underweight | below 18.5 |
| Healthy weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obese | 30 and above |
Good to know
- BMI is a rough screening measure for adults. It does not tell muscle from fat, so athletes can score as overweight while being healthy.
- It is not designed for children, teenagers or pregnancy, and some health services use different cut-offs for some ethnic groups.
- Talk to a doctor before acting on any result. This calculator gives information, not medical advice.
FAQ
What is BMI Prime? Your BMI divided by 25, the top of the healthy range. A value above 1 means a BMI above 25.
Are my height and weight stored? They are kept only in this browser so the form remembers them next time. Nothing is sent anywhere.