Calculate your BMI
Enter your height and weight to get your body mass index and its WHO weight category. For adults aged 18 and over.
Calculations run on this device. We don't see, store or log your measurements or age. This calculator gives estimates for adults and is not medical advice.
How it works
- Choose metric or imperial units.
- Enter your height and weight.
- Read your BMI and its category.
How BMI is calculated
BMI = weight in kg ÷ (height in m)². Someone 175 cm tall weighing 70 kg has a BMI of 70 ÷ 1.75² = 22.9. In imperial units the calculator converts pounds and feet first, so the result is the same.
What the categories mean
The WHO categories for adults are: under 18.5 underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight, 30 and above obesity. For Asian populations, including South Asian, WHO notes that health risks start at lower values and suggests 23 for overweight and 27.5 for obesity; the calculator shows this when it changes your category.
What BMI cannot tell you
BMI does not distinguish muscle from fat, so athletes can score high, and older adults with low muscle can score normal. It is not meant for children, teenagers or pregnancy. Source: World Health Organization. For advice about your weight, talk to a doctor.
Frequently asked questions
Is a BMI of 24 healthy?
By the standard WHO categories, yes (18.5–24.9). By the WHO cut-offs for Asian populations, it is in the overweight range (23–27.4).
Does BMI work for children?
No. Children and teenagers need age- and sex-specific BMI charts; this calculator is for adults.
Is my data stored?
No. The calculation happens on your device and nothing is sent anywhere.
Related tools
- Ideal Weight CalculatorFind the healthy weight range for your height based on WHO BMI ranges, with the Devine and Robinson formulas for comparison. Metric or imperial units.
- Calorie CalculatorEstimate how many calories you burn a day (BMR and TDEE) with the Mifflin–St Jeor formula, plus a rough target to lose or gain weight. For adults.