BMI Calculator
Check your body mass index and the healthy weight range for your height.
For information only. This calculator gives a general estimate from a standard formula and is not medical advice. It doesn't account for factors such as muscle mass, pregnancy, age-related changes or health conditions. Talk to a doctor or registered dietitian about your health.
How it works
- Choose metric or imperial units.
- Enter your height and weight.
- See your BMI, its category and the healthy weight range for your height.
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 1.75 m gives 70 ÷ 3.06 = 22.9.
What do the BMI categories mean?
For adults, the World Health Organization uses under 18.5 as underweight, 18.5–24.9 as healthy, 25–29.9 as overweight and 30 or more as obesity.
Is BMI accurate for everyone?
BMI is a quick screening measure. It does not distinguish muscle from fat, so athletes may read as overweight, and it is not designed for children, teenagers or pregnancy.
Is my data saved?
No. The calculation happens in your browser and your measurements are never sent to our servers.
What BMI tells you
Body mass index relates weight to height and is widely used as a quick screening tool for weight categories in adults. It's simple and consistent, which is why doctors and health organisations use it as a starting point.
Its limits
BMI can't tell muscle from fat or show where fat is stored, and categories may differ for some ethnic groups. Waist measurement, body fat percentage and a conversation with a health professional give a fuller picture.