How to use the BMI Calculator
Estimate adult body mass index from weight and height, with metric and US customary units. Enter the requested values, review their units, and select Calculate. The result panel shows both the answer and the substituted steps.
The formula
BMI = weight in kilograms ÷ height in meters²
Frequently asked questions
Is BMI a diagnosis?
No. BMI is a screening ratio and does not directly measure body fat, fitness, or health.
Does this calculator apply to children?
No. Children and teenagers require age- and sex-specific growth references interpreted by a qualified clinician.
Important notes
Results are estimates based on the values supplied and the formula shown. Round only at the end of a calculation, and verify safety-critical, medical, financial, or construction decisions with an appropriate professional.