BMI Calculator
Calculate your BMI, its category, and your healthy weight range.
Enter a number above 0.
CDC adult categories
For adults 20 and older. BMI doesn’t distinguish fat from muscle and is not a medical diagnosis, so talk to a professional about your health.
BMI categories
A BMI of 22.7 falls in the Healthy weight category.
CDC adult categories
| Category | BMI |
|---|---|
| Underweight | Under 18.5 |
| Healthy weight | 18.5 to under 25 |
| Overweight | 25 to under 30 |
| Class 1 obesity | 30 to under 35 |
| Class 2 obesity | 35 to under 40 |
| Class 3 obesity | 40 or greater |
BMI Calculator
BMI Calculator works out your body mass index from your height and weight and shows which category it falls in. It divides your weight by the square of your height.
BMI = weight (kg) ÷ height (m)²
154 lb at 69 in = BMI 22.7
How to use
- Enter your height and weight. You can switch between in · lb and cm · kg.
- Read your BMI, its category, and the healthy weight range for your height on the right.
- Use the table below to see where you sit and compare the other categories.
Key terms
BMI categories
These are the CDC categories for adults 20 and older. Obesity is divided into classes starting at 30, 35, and 40.
| BMI | Category |
|---|---|
| Under 18.5 | Underweight |
| 18.5 to under 25 | Healthy weight |
| 25 to under 30 | Overweight |
| 30 or greater | Obesity |
The CDC describes BMI as a screening measure that doesn’t distinguish fat, muscle, and bone. It should be considered with other factors when assessing your health.
Healthy weight for your height
This multiplies each end of the healthy BMI range by the square of your height. It is not a personal weight goal.
Lowest = 18.5 × height (m)²
Highest = 24.9 × height (m)²
At 69 in, that is about 125.3 to 168.6 lb.
BMI dates back to 1832
The Belgian mathematician and statistician Adolphe Quetelet described in 1832 that weight increases as the square of height. The ratio was known as the Quetelet Index until Ancel Keys named it the body mass index in 1972.
Can health risks start below a BMI of 25?
A 2004 WHO expert consultation concluded that a substantial share of Asian people have a high risk of type 2 diabetes and cardiovascular disease at BMIs below 25. The point where risk appears ranged from 22 to 25 across Asian populations.
The consultation kept the international categories and proposed ways for each country to set definitions for its own population.
FAQ
Is a BMI of 25 overweight?
Yes. In the CDC categories, overweight runs from 25 to under 30, and obesity starts at 30.
Can muscle make my BMI high?
Yes. BMI only uses height and weight, so it can’t tell muscle from fat. To see your share of fat, try the Body Fat Calculator as well.
Can teens use this?
These categories are for adults, so they don’t apply directly to anyone under 20.
Is what I enter saved?
No. It is never saved or sent to a server. Everything is calculated in your browser.