Adults only
Children and teenagers need age- and sex-specific BMI charts.
BMI Calculator
Calculate your body mass index from your height and weight, see which category it falls into, and find the healthy weight range for your height.
- 100% free
- No sign-up
- Runs in your browser
Your BMI
How to use
How to use the BMI Calculator
- Choose metric or imperial units.
- Enter your weight and height.
- Read your BMI, category and healthy weight range.
- Tick the Asian cut-offs option if it applies to you.
Private by design. Calculations happen in your browser. Nothing you enter is uploaded or stored.
About this tool
What BMI does and does not tell you
BMI is weight in kilograms divided by height in metres squared. For most adults, the World Health Organization classes under 18.5 as underweight, 18.5 to 24.9 as a healthy weight, 25 to 29.9 as overweight and 30 or above as obesity. Health bodies in several countries suggest lower thresholds for people of South Asian and East Asian background, because health risks can begin at a lower BMI.
BMI is a quick screening number, not a diagnosis. It does not distinguish muscle from fat, so very muscular people can score high, and it is not designed for children, teenagers or pregnant women. Waist size, activity and family history all matter too. Speak to a doctor about what is right for you.
Good to know
Good to know
Muscle counts as weight
Athletes may show a high BMI while being very fit.
Waist matters too
A large waist can signal health risks even at a healthy BMI.
Ask a professional
For personal health advice, talk to a doctor or dietitian.
FAQ
BMI Calculator FAQs
What is a healthy BMI?
For most adults, 18.5 to 24.9. Lower cut-offs are often suggested for Asian adults.
Is BMI accurate?
It is a useful screening tool for populations but can be misleading for individuals, such as athletes.
Can children use this calculator?
No. Children need BMI-for-age charts from a doctor or health service.
Is my information stored?
No. Everything is calculated in your browser.
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