Adult Body Mass Index Calculator

Body Mass Index (BMI) and waist measurement can give you an idea about your health risks. Enter the following information and calculate your BMI.
Optional

What BMI Means

Disease Risk* Relative to Normal Weight and Waist Circumference

BMI
(kg/m2)
Obesity
Class
Men 102 cm (40 in) or less
Women 88 cm (35 in) or less
Men > 102 cm (40 in)
Women > 88 cm (35 in)
Underweight
< 18.5

-
-
Normal
18.5–24.9

-
-
Overweight
25.0–29.9

Increased
High
Obesity
30.0–34.9
I
High
Very High

35.0–39.9
II
Very High
Very High
Extreme Obesity
40.0 +
III
Extremely High
Extremely High

* Disease risk for type 2 diabetes, hypertension, and CVD.
+ Increased waist circumference also can be a marker for increased risk, even in persons of normal weight.

Waist Circumference

Carrying excess body fat around your middle is more of a health risk than if weight is on your hips and thighs. Waist circumference is a better estimate of visceral fat, the dangerous internal fat that coats the organs. It is therefore a more accurate predictor of cardiovascular risk, type 2 diabetes in women and metabolic syndrome.

Measuring your waist circumference accurately

Illustration of where to place measuring tape for measuring you waist for males
Illustration of where to place measuring tape for measuring you waist for females
  1. Place the tape measure directly on your skin, or over no more than one layer of light clothing
  2. The correct place to measure your waist is halfway between your lowest rib and the top of your hipbone. This is roughly in line with your belly button
  3. Breathe out normally and measure
  4. Make sure the tape is snug, without squeezing the skin