GM Diet MagicPlain-language guides to the 7-day GM diet, with honest answers about what it can and cannot do.
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General information only, not medical advice. Talk to a doctor or registered dietitian before starting any weight-loss plan. Medical disclaimer.
BMI calculator for men and women
Work out your body mass index, then compare it with the standard and South Asian ranges below.
Calculate your BMI
| height | ft | in | |||
| weight | lb | ||||
| height | cm | |
| weight | kg |
BMI ranges for adults
| Category | Standard thresholds | Lower thresholds* |
|---|---|---|
| Underweight | Below 18.5 | Below 18.5 |
| Healthy weight | 18.5 to 24.9 | 18.5 to 22.9 |
| Overweight | 25 to 29.9 | 23 to 27.4 |
| Obesity | 30 or more | 27.5 or more |
*NICE guidance in the UK advises lower thresholds for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background, because health risks rise at a lower BMI.
How BMI is calculated
BMI is your weight in kilograms divided by your height in metres squared. For example, 70 kg at 1.70 m gives 70 ÷ (1.70 × 1.70) = 24.2.
What BMI cannot tell you
BMI is a quick screening number. It does not measure body fat or where it is stored, and it can mislead for very muscular people, older adults, and during pregnancy. It is not used for children in the same way. Waist-to-height ratio is a useful second check: NICE describes a ratio of 0.4 to 0.49 as indicating no increased health risk.
See the healthy weight chart by height for ranges in kilograms.
Sources
- NICE guideline NG246: Identifying and assessing overweight, obesity and central adiposity
- NHS inform: Body mass index (BMI)
Frequently asked questions
How is BMI calculated?
BMI is your weight in kilograms divided by your height in metres squared. For example, 70 kg at 1.70 m gives a BMI of 24.2.
What is a healthy BMI?
A BMI of 18.5 to 24.9 is the standard healthy range. For people of South Asian and some other backgrounds, NICE uses 18.5 to 22.9.
Is BMI accurate?
BMI is a screening number. It does not measure body fat and can mislead for very muscular people, older adults and during pregnancy.