Free BMI calculator
Body Mass Index (BMI) is the most widely used indicator in the world to assess whether your weight is appropriate for your height. Used by the WHO and healthcare professionals, it's calculated by dividing weight (kg) by height squared (m²).
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Try for freeWhy calculate your BMI
BMI quickly identifies whether you're underweight, normal weight, overweight or obese. It's a simple first indicator, even though it doesn't account for muscle mass. For a more precise evaluation, combine it with body fat percentage.
How to use this calculator
- 1Choose your unit system (metric or imperial)
- 2Enter your height in cm or inches
- 3Enter your weight in kg or lbs
- 4Discover your BMI and category
- 5Compare with the ideal weight range
BMI limitations
- •BMI doesn't distinguish between fat mass and muscle mass
- •A muscular athlete may have an "overweight" BMI while being in excellent health
- •BMI is less reliable for children, elderly and pregnant women
- •For more precision, also use the body fat estimator
- •BMI remains a good first indicator for the general population
Frequently asked questions
A BMI between 18.5 and 24.9 is considered normal by the WHO. Below 18.5 is underweight. Above 25 is overweight.
No, BMI doesn't differentiate between muscle and fat. A bodybuilder would be classified as "obese" despite having low body fat. Use body fat % instead.
BMI = weight (kg) / height² (m). Example: 75 kg / (1.75 m)² = 75 / 3.0625 = 24.5.
The formula is identical, but women naturally have more body fat. A BMI of 22 corresponds to different body compositions depending on sex.