How to use the BMI Calculator
- Choose metric or US units.
- Enter your weight and height.
- Press Calculate to see your BMI, category and healthy range.
Formula
BMI = weight (kg) ÷ height (m)²
In US units: BMI = 703 × weight (lb) ÷ height (in)².
| BMI | WHO category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25 – 29.9 | Overweight |
| 30 and above | Obesity |
Examples
- 70 kg, 175 cm: 70 ÷ 1.75² = 22.9, healthy weight.
- 200 lb, 5 ft 10 in: 703 × 200 ÷ 70² = 28.7, overweight.
Frequently asked questions
Is BMI accurate for athletes?
Not always. Muscle is denser than fat, so very muscular people can have a high BMI with low body fat. A waist measurement or the Body Fat Estimator adds context.
Does BMI differ for men and women?
The adult formula and cut-offs are the same for both. Body composition differs, which is one of the measure’s limitations.