Body mass index (BMI) is a number that expresses your weight in relation to your height. A BMI that falls into the “normal” range means that your weight is in reasonable proportion to your height.
Interactive BMI Calculator
An interactive online tool to calculate your BMI and interpret the results is available from the Centers for Disease Control and Prevention (CDC).
The BMI formula
BMI can be calculated with either metric units (meters and kilograms) or standard (“English”) units (inches and pounds).
The standard-unit formula to calculate your BMI is:
- start with your weight in pounds
- divide it by your height in inches squared
- multiply the result by 703
For example, the BMI for a person 5’3’’ tall who weighs 140 pounds is:
- 140 divided by 63 x 63 = 0.0353 x 703 = 24.7.
The categories for BMI are:
|
Underweight |
Less than 18.5 |
|
Normal weight |
18.5 – 24.9 |
|
Overweight |
25 – 29.9 |
|
Obese |
30 or greater |
