BMI Calculator
Calculates body mass index for adults using metric units.
Your result
Estimate only. Results update as you type.
How this calculator works
BMI = weight (kg) ÷ height (m)².
Worth knowing
BMI doesn’t measure body fat or muscle. Waist measurement is another useful check.
Guides for this calculator
- How the BMI Calculator Works (With a Worked Example)
- Getting the Most From a BMI Calculator: Tips and Common Errors
Questions
- Are these calculators medical advice?
- No. They provide general information. See your GP or visit healthdirect.gov.au for personal advice.
- Do they work for children?
- No. Adult formulas are used throughout. Children’s growth is assessed differently.
- Where do the formulas come from?
- Each calculator page names the formula used, such as Mifflin-St Jeor for BMR or the US Navy method for body fat.
This calculator gives general estimates using published Australian rates and formulas. It doesn’t consider your personal circumstances. Check current figures with the ATO, your state government or a qualified professional before making decisions. See our disclaimer.