BMI and waist calculator
Enter your height and weight. Waist is optional, but it shows what BMI cannot: where the fat sits.
How it works
BMI is weight in kilograms divided by height in meters squared, or weight in pounds × 703 divided by height in inches squared. For most adults, a BMI of 18.5 to 24.9 counts as a healthy weight, 25 or more as overweight, and 30 or more as obesity.
For people of South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean background, the NHS uses lower cutoffs: 23 to 27.4 is overweight and 27.5 or more is obesity.
Waist: the NHS advises keeping it under half your height, and suggests this measure for adults with a BMI under 35.
What it cannot know
BMI cannot tell muscle from fat, and it does not apply to children, teenagers, or pregnancy. Treat the number as a prompt, not a diagnosis.
These are estimates for adults, not a diagnosis. If you have a health condition, are pregnant, or take medication, go over the numbers with your doctor.
Read more
- BMI and waist-to-height ratio: what your numbers mean
- exercise and visceral fat
- Calorie calculator
- Steps to calories calculator