BMI Calculator
Calculate body mass index in metric or imperial units, with the healthy range for your height.
Your result will appear here as soon as you add some input.
How to use it
- 1Enter your values in the fields above.
- 2The answer and the working appear immediately below.
- 3Check the working to see the formula with your numbers substituted.
Formulas used
- BMI = weight in kg / (height in metres)^2
About the BMI Calculator
BMI was designed in the 1830s to describe populations, not individuals. It is a ratio of weight to height squared and knows nothing about body composition.
It systematically misclassifies muscular people as overweight and can miss excess body fat in older adults who have lost muscle. The standard categories were also derived largely from European populations and fit others less well.
The healthy weight range shown is the range that produces a BMI between 18.5 and 24.9 at your height.
Questions people ask
Is BMI a reliable measure of health?
Only as a rough population-level screen. It ignores muscle mass, fat distribution, age, sex and ethnicity, and it says nothing about fitness or metabolic health. Waist measurement and a conversation with a clinician tell you far more.
Is your figures uploaded to a server?
No. This tool runs entirely in your browser using standard web APIs, so your figures never leaves your device. You can confirm it by opening your browser's network panel while the tool runs, or by disconnecting from the internet after the page has loaded.
Is it free, and do I need an account?
Yes, it is free, and there is no account, no sign-up and no watermark on the result. The project is funded by optional donations.