Home › Free tools › BMI Calculator
BMI Calculator
Enter your weight and height in metric or imperial units to get your BMI, its WHO category and your healthy weight range. You can switch to Asian cut-offs. Everything runs in your browser – nothing is uploaded or saved.
Formula and ranges
BMI = weight (kg) ÷ height (m)². In imperial units: 703 × lb ÷ in². WHO ranges are under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight and 30 or more obesity. For people of Asian descent, many health bodies use lower cut-offs: healthy up to 22.9, overweight 23–24.9 and obesity from 25. BMI is a screening number, not a diagnosis.
🔒 Privacy: this tool runs entirely in your browser. Nothing you type is saved, uploaded or sent anywhere – close the tab and it is gone.
Frequently asked questions
Is BMI accurate for athletes?
Not always. Muscle weighs more than fat, so BMI can overestimate.
Why are the Asian cut-offs lower?
Health risks start at a lower BMI in many Asian populations.
Does it work for children?
No. Children need age- and sex-specific percentile charts.
Is my data saved?
No.