BMI Calculator
Calculate Body Mass Index. Metric and imperial. WHO classification.
BMI Calculator
How it works
- 1.
Pick units
Pick metric (cm/kg, international) or imperial (ft-in/lb, USA). Internally the tool always computes in SI and returns the result in your chosen system.
- 2.
Enter height and weight
Enter height and weight. Formula: BMI = weight (kg) / height (m)². Imperial values are converted to SI before the calculation.
- 3.
Read BMI and category
BMI value plus WHO classification (underweight, normal, overweight, obesity I-III) with color coding and the healthy weight range for your height.
FAQ
Which formula is used?+
Kilograms divided by height in meters squared. Same formula in both unit systems.
Does this apply to children?+
No, children and adolescents need age- and sex-specific percentiles. This calculator is for adults.
Is BMI the best metric?+
BMI is a rough estimate. It doesn't account for muscle mass or body composition. Consult a doctor for medical decisions.