Find your body mass index (BMI) from your height and weight. Use US or metric units. For ages 2 to 19, you also see the CDC percentile.
For information only. BMI is a screening tool. It does not diagnose a health problem. Talk to a health care provider about your weight and your health.
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How BMI is calculated
BMI equals the weight in kg divided by the height in meters, squared.
In US units, BMI equals 703 times the weight in lb, divided by the height in inches, squared.
Example: a person weighs 70 kg and is 175 cm tall. The height is 1.75 m. BMI equals 70 divided by 1.75 squared. That is 22.9.
How to use it
Choose your units: US or metric.
Choose Adult, or Child or teen.
Type your height and your weight. For a child, also choose the sex and type the age.
Read your BMI and your category. The result changes as you type.
Divide your weight in kg by your height in meters, squared. In US units, multiply your weight in lb by 703. Then divide by your height in inches, squared. The calculator does this for you.
What are the adult BMI categories?
Below 18.5 is underweight. From 18.5 to 24.9 is a healthy weight. From 25 to 29.9 is overweight. A BMI of 30 or more is obesity. Class 1 is 30 to 34.9. Class 2 is 35 to 39.9. Class 3 is 40 or more.
Can I use the calculator for a child or teen?
Yes, from 2 to 19 years old. Choose Child or teen. Choose the sex and type the age. The calculator shows the BMI percentile and the CDC category.
Does BMI diagnose a health problem?
No. BMI is a screening tool. It does not diagnose the health of a person. Talk to a health care provider about your weight and your health.
Does the calculator send my height and weight to a server?
No. The calculator works in your browser and sends nothing. Your height, weight and age stay on your device. The page saves nothing. Read more about privacy.