HEALTH TOOL

BMI Calculator

Calculate Body Mass Index from height and weight, in metric or imperial.

BMI

Category

About this tool

Body Mass Index (BMI) is a simple screening measure calculated from height and weight. It's widely used as a quick starting point, though it doesn't distinguish muscle from fat and isn't a diagnosis on its own — it's worth reading alongside other measures and, where relevant, a conversation with a healthcare provider.

Switch between metric (kilograms and centimeters) and imperial (pounds and inches) with the toggle above — the calculation updates immediately either way.

Frequently asked questions

How is BMI calculated?
Metric: weight in kilograms divided by height in metres, squared. Imperial: weight in pounds multiplied by 703, divided by height in inches, squared.
What do the categories mean?
Under 18.5 is classified as underweight, 18.5–24.9 as a typical range, 25–29.9 as overweight, and 30+ as obese. These are general population screening bands, not individual medical advice.
Is BMI accurate for everyone?
It's a population-level screening tool. It can be less informative for athletes with high muscle mass, older adults, and some other groups — it's one data point, not a full picture of health.