BMI Calculator
Enter your height and weight to see your body mass index and adult BMI category, plus the weight range that matches a BMI of 18.5 to 24.9 at your height. It runs in your browser and nothing is saved.
Calculate your BMI
How to calculate your BMI
- Choose metric (cm, kg) or imperial (feet, inches, pounds).
- Enter your height and weight.
- Press Calculate BMI to see the number, the adult category and a healthy weight range for your height.
How BMI is calculated
BMI is weight in kilograms divided by height in metres squared. A person who is 70 kg and 175 cm tall has a BMI of 70 ÷ 1.75² = 22.9. With imperial units, BMI is 703 × weight in pounds ÷ height in inches squared. For example, 160 lb at 5 ft 9 in (69 in) gives 703 × 160 ÷ 69² = 23.6.
Adult BMI categories
| BMI | Category |
|---|---|
| Under 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight |
| 25.0 to 29.9 | Overweight |
| 30.0 and over | Obesity |
These are the standard adult categories used by the World Health Organization and many national health services.
What BMI cannot tell you
BMI is a screening number, not a diagnosis. It does not separate muscle from fat, so athletes and very muscular people can score high. It does not show where fat is carried, and some health bodies use different cut-offs for people of Asian descent. It is not suitable for children, teenagers or pregnancy. For a personal assessment, talk to a doctor or other qualified health professional.
Healthy weight range for your height
The result also shows the weights that would give a BMI between 18.5 and 24.9 at your height. For someone 175 cm tall that is roughly 56.7 to 76.3 kg. Treat it as a general guide rather than a target.
Frequently asked questions
What is a healthy BMI?
For most adults, a BMI from 18.5 to 24.9 is classed as a healthy weight.
How do I calculate BMI in pounds and feet?
Multiply your weight in pounds by 703, then divide by your height in inches squared. Or choose Imperial above.
Is BMI accurate for athletes?
Often not. Muscle weighs more than fat, so a very muscular person can have a high BMI without carrying excess fat.
Can I use this BMI calculator for children?
No. Children and teenagers are assessed against age and sex growth charts, not adult categories.
Is my data saved?
No. The calculation runs in your browser and nothing is stored or sent.
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