BMI Calculator
BrainZig is a fun and easy app for calculating the BMI using your weight and height. BMI stands for Body Mass Index that allows you to categorize your health status- healthy, over-weight, or obese.
BMI is a number that indicates the approximate body weight as per your height. It is not to measure your body fat and muscle mass. It is commonly used to check whether a person healthy body weight based on the specific height. The BMI varies from individuals based on different categories of age.
BMI formula
The formula of BMI = kg/m2
Kg is a person’s weight in kilograms
m2 is their height in meters squared.

BMI table for children and teens, age 2-20
The Disease Control and Prevention (CDC) recommend BMI for children and teens for age 2-20.
Category |
Percentile Range |
Underweight |
<5% |
Healthy weight |
5%-85% |
At risk of overweight |
85%-95% |
Overweight |
>95% |
BMI charts for adults, age 20-60
If you are 20 years or above, you’re BMI can be under any of the categories given below:
Category |
BMI range - kg/m2
|
Underweight |
below 18.5 |
Healthy weight |
from 18.5 to 24.9 |
At risk of overweight |
from 25 to 29.9 |
Overweight |
over 30 |
Calculate your BMI today to find out in which category you come under.
Pregnant women
Usual BMI does not apply if the woman is pregnant.
Limitations of BMI
BMI is extensively used for finding healthy body weight, but it does have limitations. The BMI is the only estimation but it is important to also consider other body compositions, muscle, bone mass, and fat.
Is Body Mass Index meant to consider?
Not exactly! Body mass index is a measure of your weight and height; therefore it does not always give you an accurate value. Therefore, carefully find your exact health status- overweight and underweight as it might lead to so many other health issues.
For adults, if your BMI is over 35, you are more likely to have weight-related issues. Therefore, it is important to keep a track of it, but don’t totally depend on it.