How to use
- Choose metric (cm, kg) or US units (feet, inches, pounds).
- Enter your height and weight.
- Choose the WHO standard or the Chinese adult standard.
- Read your BMI, category and healthy weight range.
Options explained
- WHO standard
- Underweight below 18.5, normal 18.5–24.9, overweight 25–29.9 and obese from 30, with obesity classes II from 35 and III from 40.
- China standard
- WS/T 428—2013 uses lower cut-offs for Chinese adults — normal 18.5–23.9, overweight 24–27.9 and obese from 28 — because health risks rise at lower BMI.
Examples
| Height | Weight | BMI | WHO | China |
|---|---|---|---|---|
| 175 cm | 70 kg | 22.9 | Normal | Normal |
| 170 cm | 70 kg | 24.2 | Normal | Overweight |
Frequently asked questions
How is BMI calculated?
Weight in kilograms divided by height in metres squared. 70 kg at 1.75 m gives 70 ÷ 1.75² = 22.9.
Is BMI accurate for everyone?
No. It does not tell muscle from fat, so athletes can appear overweight, and it is not used for children, teenagers or pregnant women. Waist size and body fat give a fuller picture.
Is my data stored?
No. The calculation runs in your browser and nothing is saved.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.