BMI Calculator
Body mass index (BMI) estimates body size from height and weight. It is a screening number, not a diagnosis. Muscle, age, and ethnicity affect how well BMI maps to health risk, so use it as a starting point with a clinician.
BMI24.2
CategoryNormal weightWHO adult classification
Not medical advice. Talk to a qualified clinician about your health.
Formula
BMI = weight (kg) ÷ height (m)². In US units: BMI = 703 × lb ÷ in².
How to use this calculator
- Choose metric or US units.
- Enter your weight and height.
- Read BMI and the WHO adult category.
Examples
Metric example
A person who is 170 cm and 70 kg has BMI = 70 ÷ 1.70² ≈ 24.2 (normal weight).
US example
A person who is 5 ft 7 in and 150 lb has BMI ≈ 23.5.
FAQ
What is a healthy BMI?+
For most adults, WHO lists 18.5–24.9 as normal. Athletes and older adults may need a different interpretation.
Is BMI accurate?+
BMI does not measure fat directly. It is a quick population screening tool, not a complete health assessment.
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