BMI calculator
Weight ÷ height² with WHO, Asian, or JASSO Japan cutoffs. The number stays the same; the category label follows the table you select.
Defaults to your region. Switch to compare any other scale.
Overweight ≥25, obesity ≥30.
Result
24.1
BMI
Normal range
- Band on this standard18.5–24.9
Normal range
BMI does not separate fat from muscle. Athletes and older adults should read it with a clinician.
About this tool
Body mass index (BMI) is weight divided by height squared. Clinics still use it as a quick screening index, but cutoffs are not universal: WHO adult bands start overweight at 25, many Asian guidelines at 23, and Japan’s JASSO obesity threshold is 25.
Enter height and weight in metric or imperial units, then choose the regional standard that matches the advice you were given. The category label follows that table — switching standards changes the label, not the underlying BMI number.
BMI is not a diagnosis. Muscle mass, waist circumference, age, and clinical history matter for individual decisions. Pair this page with the calorie calculator when you are exploring energy needs alongside body-mass screening.
Formula
BMI = kg ÷ m²BMI = (lbs ÷ in²) × 703
How it is calculated
- Enter height and weight in metric or imperial units.
- BMI is weight divided by height squared (×703 if imperial).
- Read the category for the selected regional cutoff.
- If your country, school or provider uses different rules, pick another option in the “Standard” menu at the top.
Questions
Why is Asian overweight 23, not 25?
WHO expert groups noted higher metabolic risk at lower BMI in many Asian populations. India, Japan, and several ASEAN guidelines use 23/25.
Is BMI a diagnosis?
No. It is a screening index. Waist, body fat, and clinical history matter more for decisions.
Metric or imperial — does the formula change?
BMI is still weight ÷ height². Imperial multiplies by 703 so pounds and inches yield the same index as kilograms and metres.
When should I change the “Standard” setting?
When the rules you work with differ from the default chosen for your language. Options on this page: WHO / CDC adult; WHO Asian cutoff; Japan (JASSO). The formula, steps and result update to match your choice.