BMI calculator
Body mass index in kg and cm or stone, pounds, feet and inches, with the healthy weight range for your height.
Your BMI
22.9
Healthy weight
- Healthy weight for your height
- 56.7 kg – 76.3 kg
Show workings
- Height1.75 m
- Weight70 kg
- BMI70 ÷ (1.75 × 1.75) = 22.9
How it works
BMI is your weight in kilograms divided by your height in metres squared. For adults the usual ranges are:
- below 18.5: underweight
- 18.5 to 24.9: healthy weight
- 25 to 29.9: overweight
- 30 or more: obese
BMI is a quick screening measure, not a diagnosis. It doesn't distinguish muscle from fat, and isn't suitable for children, during pregnancy, or for some athletes. People of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background are advised to use lower thresholds (23 and 27.5). Talk to a GP or health professional about your health.
Worked example
Someone 1.75 m tall weighing 70 kg: 70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 = 22.9, in the healthy range. At that height, the healthy range is about 56.7 to 76.3 kg.
Questions
Is BMI accurate for everyone?
No. Muscular people can have a high BMI while being healthy, and older adults may have a normal BMI but less muscle. Waist size is another useful check: for most adults, it should be less than half your height.
Can children use this?
No. Children's BMI is compared with growth charts for their age and sex; use the NHS BMI calculator for children or ask a health visitor or GP.
Is my data saved anywhere?
Only on this device, so it's there when you come back. It's never sent to us and isn't added to the page link. You can clear it from the privacy page.