BMI calculator
Get your body mass index, its category and the healthy weight range for your height.
Your BMI
25.1
Overweight
- Healthy weight for your height
- 125–169 lb
- Healthy BMI range
- 18.5 – 24.9
How to use the bmi calculator
- Choose US units (feet, inches, pounds) or metric (centimeters, kilograms).
- Enter your height and weight.
- Read your BMI, its category and your healthy weight range.
About this calculator
Body mass index compares weight with height. It is a quick screening number used by doctors and insurers, not a diagnosis: it cannot tell muscle from fat and reads high for very muscular people.
Alongside your BMI, the calculator shows the weight range that corresponds to a BMI of 18.5 to 24.9 for your height, which is often more useful than the single number.
Body mass index
BMI = weight (kg) ÷ height (m)² · BMI = 703 × weight (lb) ÷ height (in)²
Adult categories: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30 and above obesity.
Example
At 5 ft 9 in (69 inches) and 170 lb, BMI is 703 × 170 ÷ 69² ≈ 25.1, just into the overweight range. The healthy range for that height is about 125 to 168 lb.
Frequently asked questions
For general information only, not medical advice. Talk to a healthcare professional about your health.
What is a healthy BMI?
For adults, 18.5 to 24.9 is classed as healthy weight by the CDC and WHO. Some populations have different risk thresholds, for example lower cut-offs are often used for people of Asian descent.
Is BMI accurate?
It is a useful screening tool for populations but imperfect for individuals. It does not measure body fat directly and overestimates fatness in muscular people. Waist size and other measures add context.
Does BMI work for children?
Not with adult categories. Children and teens use BMI-for-age percentiles that account for growth and sex.
Does age or sex change BMI?
The adult formula is the same for everyone. Body composition does change with age and sex, which is one reason doctors look at more than BMI.