How to use this tool
Choose metric or imperial measurements and enter an adult's height and weight. The BMI formula divides mass in kilograms by height in meters squared. The result includes broad WHO adult BMI categories.
Quick steps
- Choose metric (kg/cm) or imperial (lb/in) measurements.
- Enter adult weight and height to see BMI and its broad category.
- Review the healthy-range reference and the limitations of BMI.
Practical tip
BMI is only a screening measure. It does not distinguish body fat from muscle or assess age-specific needs. It is not intended for children, pregnancy or clinical diagnosis.
Common questions
How is BMI calculated?
BMI is kilograms divided by the square of height in meters. The imperial equivalent multiplies pounds per inch squared by approximately 703.07.
Is BMI accurate for athletes?
BMI may classify very muscular adults differently because it cannot distinguish muscle mass from fat mass.
Can I use this BMI calculator for children?
No. Children's BMI needs age- and sex-specific percentile charts, not the adult category thresholds used here.