BMI Calculator — Body Mass Index
Calculate your BMI using weight and height. Available in metric (kg/cm) and imperial (lb/inches). Results include WHO BMI category classification.
BMI calculator
WHO BMI categories
| BMI range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight ✓ |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obese Class I |
| 35.0+ | Obese Class II/III |
Important: BMI is a screening tool, not a diagnosis. It does not account for muscle mass, bone density, or fat distribution. Athletes often have high BMI despite being very healthy. Consult a healthcare professional for a complete assessment.
Frequently asked questions
BMI is a useful screening tool but has limitations. It may overestimate body fat in muscular individuals and underestimate it in older adults. It also does not distinguish between visceral and subcutaneous fat.
The WHO defines 18.5–24.9 as healthy weight for most adults. However, BMI ranges for people of Asian descent are slightly lower — some guidelines use 18.5–22.9 as healthy for this group.
Multiply kilograms by 2.20462 to get pounds. Example: 70 kg × 2.20462 = 154.3 lbs. Use our unit converter for more conversions.