How can I work out my body mass index (BMI)?

To work out your BMI:

  • divide your weight in kilograms (kg) by your height in metres (m)
  • then divide the answer by your height again to get your BMI

For example:

  • If you weigh 70kg and you're 1.75m tall, divide 70 by 1.75. The answer is 40.
  • Then divide 40 by 1.75. The answer is 22.9. This is your BMI.

Try the BMI healthy weight calculator to find out your BMI.

For more information, including advice on when your BMI is above or below the ideal weight range, see What is the body mass index (BMI)?

Read the answers to common health questions about exercise.

Further information:


Video: understanding BMI results in adults

An expert explains how to calculate your BMI (body mass index) and interpret the results correctly. He also discusses the health risks associated with a BMI that is too low or too high.

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Page last reviewed: 24/07/2012

Next review due: 23/07/2014