BMI Calculator
Calculate your Body Mass Index (BMI) from height and weight. Supports metric and imperial units with instant category feedback.
Examples
See what this tool can do.
Check your BMI band
Enter height and weight to see whether you fall in the healthy range.
Compare units
Switch between metric and imperial without recalculating by hand.
Tips & tricks
Get the most out of it.
- 1Use the same units consistently for accurate results.
- 2BMI is a guide — discuss health decisions with a professional.
- 3Muscle mass can push BMI up without indicating excess fat.
About BMI Calculator
What this tool does
BMI Calculator works out your Body Mass Index from height and weight, in metric or imperial units, and shows the category.
How to use it
- Choose metric or imperial units.
- Enter your height and weight.
- Read your BMI and its category.
How it works
BMI is weight in kilograms divided by height in metres squared (kg/m²); imperial inputs are converted first. The result is mapped to the standard WHO categories.
Important considerations
- BMI is a general screening measure, not a diagnosis.
- It doesn't distinguish muscle from fat, so athletes and some body types read high.
Privacy
This tool runs entirely in your browser. Nothing you enter is uploaded to a server.
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Frequently asked questions
For adults, the standard healthy range is roughly 18.5–24.9. Below is underweight, 25–29.9 is overweight, and 30+ is obese — as general categories, not diagnoses.