Calculators
BMI Calculator: Body Mass Index for Adults
Enter your height and weight in metric or imperial units (feet and inches, pounds or stone) to see your body mass index, the adult category it falls in and the healthy weight range for your height. This is not medical advice.
Enter your height and weight to see your BMI.
| Underweight | Below 18.5 |
| Healthy weight | 18.5 to 24.9 |
| Overweight | 25 to 29.9 |
| Obesity class I | 30 to 34.9 |
| Obesity class II | 35 to 39.9 |
| Obesity class III | 40 or more |
This is not medical advice. BMI is a rough guide for adults; it doesn’t apply to children, teens or pregnancy, and it can’t tell muscle from fat. Your numbers stay on your device.
How to use the BMI Calculator
- Choose metric (cm and kg) or imperial (feet, inches and pounds or stone).
- Enter your height and weight.
- Read 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 is 70 ÷ (1.75 × 1.75) = 22.9.
- What is a healthy BMI?
- For adults, the World Health Organization uses these bands: under 18.5 underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight, and 30 or more obesity.
- Is BMI accurate for everyone?
- No. BMI doesn't tell muscle from fat, so athletes can score high, and it doesn't apply to children, teens or pregnancy. Some health services use different cut-offs for some ethnic groups.
- Is this medical advice?
- No. This calculator is for general information only and is not medical advice. Talk to a doctor or other health professional about your weight and health.
- Are my height and weight saved?
- No. The calculation happens on your device and nothing you enter leaves it.
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