Calculate your Body Mass Index from height and weight in metric or imperial units. BMI is a general screening indicator, not a diagnosis — it does not account for muscle mass, age, or body composition.
| Category (WHO) | BMI range |
|---|---|
| Underweight | < 18.5 |
| Normal range | 18.5 – 24.9 |
| Overweight | 25.0 – 29.9 |
| Obesity | ≥ 30.0 |
Note: BMI is a population-level screening tool. Athletes, older adults, and pregnant people should interpret it with a healthcare professional.
What is BMI and How is it Calculated?
Body Mass Index (BMI) is weight in kilograms divided by height in meters squared (kg/m²). It was designed as a simple population-level screening measure and is used by the WHO to categorize weight status ranges.
BMI does not distinguish between muscle and fat mass. A muscular athlete can have a "high" BMI with low body fat, and an older adult can have a "normal" BMI with low muscle mass. Treat it as one indicator among many, and discuss results with a healthcare professional.