Body mass index is the ratio of your weight to the square of your height, and shows which range your weight falls into. Enter your height and weight to see your result in seconds.
Enter your height and weight to calculate your body mass index.
What BMI is, how it's calculated, and where it should be interpreted with caution.
Body mass index (BMI) is the ratio of weight to the square of height; a simple screening measure that shows which range an adult's weight falls into relative to their height.
Weight (kg) is divided by the square of height (m). For example, for a weight of 70 kg and a height of 1.75 m, the index works out to around 22.9.
According to the World Health Organization's classification, an index below 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight, and 30 and above is obese.
BMI doesn't directly measure body fat percentage and doesn't distinguish between muscle and fat; it may not give an accurate picture for muscular athletes, older adults, or pregnant women.
The World Health Organization's standard classification for adults.
| Category | Body mass index |
|---|---|
| Underweight | Below 18.5 |
| Normal weight | 18.5 to 24.9 |
| Overweight | 25 to 29.9 |
| Obese | 30 and above |
Body mass index is only a general screening measure, not a medical diagnostic tool; it doesn't account for body composition, fat distribution or individual circumstances. Consult a doctor or coach for a more accurate assessment.