BMI Calculator
Enter your weight and height to get your BMI and its category.
Updated
Report a problem
Formula
- Metric:
BMI = weight (kg) ÷ height (m)² - Imperial:
BMI = 703 × weight (lb) ÷ height (in)²
Categories
| BMI | Category |
|---|---|
| below 18.5 | Underweight |
| 18.5 to 24.9 | Normal weight |
| 25 to 29.9 | Overweight |
| 30 or more | Obese |
Worked example
70 kg and 175 cm: height is 1.75 m, so 1.75² = 3.0625, and 70 ÷ 3.0625 = 22.9, which is normal weight.
Frequently asked questions
What is BMI?
Body mass index is your weight in kilograms divided by your height in metres squared. It is a quick screening number, not a diagnosis.
What is a healthy BMI range?
For most adults the World Health Organization range for normal weight is 18.5 to 24.9. Below 18.5 is underweight, 25 to 29.9 is overweight and 30 or more is obese.
How do I calculate BMI in pounds and inches?
Multiply your weight in pounds by 703 and divide by your height in inches squared. For 154 lb and 69 in that is 703 × 154 ÷ 4761 = 22.7.
Is BMI accurate for everyone?
No. BMI does not separate muscle from fat, and the ranges are for adults. Athletes, older adults, children and pregnant women should ask a health professional.