BMI Calculator

Calculate body mass index in metric or imperial units.

Height in cm, weight in kg

Enter a value for all required fields.

About this calculator

Estimate body mass index from height and weight using metric or imperial units.

How to use

  1. Choose metric or imperial.
  2. Enter height and weight.
  3. BMI and category update automatically.
  4. Use Reset to clear inputs, or Copy to copy the result.

Formula

Metric: BMI = weightKg / (heightCm / 100)²
Imperial: BMI = (weightPounds / totalInches²) × 703

Example

170 cm, 65 kg ≈ 22.49
5 ft 10 in, 160 lb ≈ 22.96

FAQ

What do the BMI categories mean?

Common adult reference bands are underweight (under 18.5), normal (18.5–24.9), overweight (25–29.9), and obesity (30+). They are general labels, not a diagnosis.

Why might BMI not fit everyone?

Muscle mass, age, pregnancy, and other factors can change how BMI relates to health. Treat the number as a starting reference only.

This BMI calculator is a reference tool only and is not medical advice. Results may not apply the same way for children, older adults, pregnancy, or athletes. Talk to a qualified health professional for personal guidance.

Results are for informational purposes only. Verify important calculations independently.