Body Mass Index (BMI) and weight calculation for adults at age 20 or older.

Are you overweight? Body Mass Index or BMI is a useful tool to assess weight status in adults, using height and weight to determine the amount of body fat. Use BMI Calculator below to determine if you are underweight, at a healthy (normal) weight, overweight or obese.

For children and teens, between the ages of 2 and 19 years, use BMI Calculator for Children and Teens.
Choose Unit:
Input Height:

Input Weight:

BMI and Weight Status:
Underweight BMI: less than 18.5
Normal BMI: 18.5 to 24.9
Overweight BMI: 25 to 29.9
Obese BMI: 30 or greater
Calculated BMI:


Do you know your BMI? For your good health, you should know your BMI.

Body Mass Index (BMI) is a measure of body fatness based on a person's height and weight. BMI is an easy method to screen for healthy body weight based on a person's height. When using kilograms and meters for weight and height, BMI is calculated by dividing the weight (W) by the squared height (H): BMI=W/. When using pounds and inches for weight and height, the formula to calculate BMI is: BMI=(W/) x 703.

The BMI weight categories are: underweight (BMI range: less than 18.5), normal or healthy weight (BMI range: 18.5 to 24.9), overweight (BMI range: 25 to 29.9), and obese (BMI range: 30 or greater). The obese category is further divided into: obese (BMI range: 30 to 34.9), severely obese (BMI range: 35 to 39.9), and morbidly obese (BMI range: 40 or greater). Click here to see BMI Charts » 
Related Conversion Tool