BMI Calculator
Calculate your body mass index from height and weight.
BMI
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Usage examples
Getting a rough BMI reading before a checkup
Before your health checkup results come back, get a quick sense of which BMI range your current height and weight fall into.
Switching between metric and imperial units
Whether you think in kg and cm or lb and ft/in, calculate BMI the same way just by switching units.
Comparing BMI before and after a weight change
Try entering a target weight to see how the BMI range shifts between where you are now and where you're aiming for.
Frequently asked questions
Is my information sent to a server?
No. The calculation happens entirely in your browser, and the height or weight you enter is never sent to a server.
How is BMI calculated?
In metric units, it's weight (kg) divided by height (m) squared. In imperial units, it's weight (lb) divided by height (in) squared, multiplied by 703.
Where do the BMI category ranges come from?
This uses the standard adult ranges from the World Health Organization: under 18.5 is underweight, 18.5–24.9 is normal, 25–29.9 is overweight, and 30 or above is obese.
Can I judge my overall health from BMI alone?
No. BMI is a simple measure based only on height and weight, so it doesn't account for muscle mass, body fat distribution, age, or sex. Treat it as a rough reference and talk to a healthcare professional for an accurate picture of your health.