Bmi calculator

BMI calculations

Body Mass Index is calculated using either the metric or imperial BMI formula. In both cases, you divide your weight by your height raised to the power of 2. With the imperial BMI formula, you then multiply the resulting figure by 703.

If you wish to calculate your BMI manually rather than using the BMI calculator, I've included some simple instructions and formulae below.

It's important that if you use these, you ensure that your units are in the same unit system (metric or imperial) and the correct corresponding unit.

If you need to convert between units of weight, use our kilos and pounds converter.

To calculate your BMI

1. Divide your weight (lb) by your height (in).
   Example: 154lb ÷ 71in = 2.169
2. Divide your answer from part 1 by your height again.
   Example: 2.169 ÷ 71 = 0.03055
3. Multiply your answer from part 2 by 703.
   Example: 0.03055 × 703 = 21.48

For kg and meters/metres

1. Divide your weight (kg) by your height (m).
   Example: 65kg ÷ 1.83m = 35.519
2. Divide your answer from part 1 by your height again.
   Example: 35.519 ÷ 1.83 =
   how to calculate your bmi in lbs
   how do you figure out your bmi in pounds