BMI Calculator

Calculate Body Mass Index in metric or imperial units.

Note: BMI is a general screening measure only and is not medical advice. It does not account for muscle, age, or individual health factors. Speak to a healthcare professional about your health.

The BMI formula

Metric: BMI = weight (kg) ÷ height (m)2. Imperial: BMI = 703 × weight (lb) ÷ height (in)2.

Worked example

At 70 kg and 175 cm (1.75 m): BMI = 70 ÷ 1.75² = about 22.9, which falls in the healthy weight range (18.5–24.9).

How to use this calculator

  1. Choose metric or imperial units.
  2. Enter weight and height in those units.
  3. Select Calculate.

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Frequently asked questions

What is a healthy BMI range?

For most adults, 18.5 to 24.9 is classified as healthy weight, below 18.5 as underweight, 25 to 29.9 as overweight, and 30 or above as obesity.

Is BMI accurate for athletes?

BMI can misclassify muscular people because it cannot distinguish muscle from fat. It is a screening tool, not a diagnosis.