Health & Fitness · Free tool
BMI Calculator
Calculate Body Mass Index in metric or imperial units. See your category and what it means, in plain English.
Updated April 2026
Your BMI
23.5
Normal weight
WHO BMI ranges
- Underweight: < 18.5
- Normal: 18.5 – 24.9
- Overweight: 25.0 – 29.9
- Obese: 30.0+
BMI is a rough screen, not a diagnosis. Muscle mass and body composition matter.
What it does
A free BMI (body mass index) calculator that takes metric or imperial inputs and returns your BMI plus the WHO classification: underweight, normal, overweight, or obese. Runs in your browser with no tracking.
BMI is a rough screening tool, not a diagnosis. It doesn’t account for muscle mass, frame size, or body composition — a lean athlete can register as “overweight” on BMI while being in peak health. Use it as one data point among several, not as the defining measure of fitness.
How to use it
- Pick metric (cm / kg) or imperial (ft, in / lb).
- Enter your height and weight.
- Read your BMI and the WHO category it falls in.
- Treat it as a screening number, not a verdict.