Calculate Body Mass Index with both WHO and Asia-Pacific classifications, and toggle between metric or imperial units.
This tool runs entirely in your browser. Your height, weight, and BMI are never sent anywhere.
BMI is calculated by dividing weight in kilograms by height in meters squared. Two classification systems are in common use:
BMI = weight(kg) ÷ height(m)²BMI = (weight(lbs) × 703) ÷ (height(inches)²)| Category | WHO (kg/m²) | Asia-Pacific (kg/m²) |
|---|---|---|
| Underweight | < 18.5 | < 18.5 |
| Normal | 18.5 – 24.9 | 18.5 – 22.9 |
| Overweight | 25.0 – 29.9 | 23.0 – 24.9 |
| Obese | ≥ 30.0 | ≥ 25.0 |
The original WHO BMI thresholds were published in 1997 based predominantly on European and North American population data. Research in subsequent decades showed that East and Southeast Asian populations face higher risk of type 2 diabetes and cardiovascular disease at significantly lower BMI values than Caucasian populations.
In 2000, the WHO Asia-Pacific Guidelines recommended lowered action points:
Sources: WHO Asia-Pacific Guidelines (2000); National Heart, Lung, and Blood Institute (NHLBI); Japan Society for the Study of Obesity.
We verified calculations against standard reference values:
| Test Case | Expected BMI | Our Result | Match |
|---|---|---|---|
| 170 cm · 65 kg | 22.49 | 22.49 | ✅ |
| 5'7" · 143 lbs | 22.41 | 22.41 | ✅ |
| 160 cm · 70 kg | 27.34 | 27.34 | ✅ |
| 180 cm · 55 kg | 16.98 | 16.98 | ✅ |
All values checked against calculator.net and CDC reference tables. Last verified: September 2026.
WHO cutoffs were set using mostly European and North American populations. Asian populations tend to have higher body fat percentage at lower BMI values, so the WHO Asia-Pacific Guidelines lowered cutoffs to 18.5 / 23 / 25 for Underweight / Normal / Overweight / Obese.
BMI is a general population screening tool and does not account for muscle mass, bone density, or pregnancy. Athletes with high muscle mass may score as 'Overweight' despite low body fat. Pregnant people should use specialized prenatal weight gain guidelines.
No. All calculations happen entirely in your browser. Your height, weight, and BMI values are never transmitted to any server.
For WHO standards, Normal BMI is 18.5 – 24.9. For Asia-Pacific standards, the Normal range is 18.5 – 22.9. Always interpret BMI alongside waist circumference, body fat percentage, and other health markers.
Yes. Toggle between Metric (cm/kg) and Imperial (ft/in, lbs). The tool converts internally using the standard formula: BMI = weight(kg) / height(m)².
If the number leaves you with more questions, set a target with the Ideal Weight Calculator, look past BMI with the Body Fat Calculator, and turn the goal into a daily budget in the Calorie Calculator.
If you just finished with BMI Calculator, the natural next steps are Unit Converter, Age Calculator, Percentage Calculator, or browse every tool in Daily Tools.