Child BMI: Body Mass Index Calculator for Children

Author: Disabled World
Published: 2010/12/27 - Updated: 2023/05/17
Peer-Reviewed: N/A
Contents: Summary - Main - Related Publications

Synopsis: Calculate the BMI measurement of your child or children using our online Body Mass Index calculator for children aged 1 to 20 years. Body Mass Index (BMI) is also known as Quetelet Index after Adolphe Quetelet the mathematician who developed the scale. BMI is defined as the body mass divided by the square of the body height.

Main Digest

So What Exactly is Body Mass Index (BMI)?

The body mass index (BMI), or Quetelet index, is defined as a value derived from the mass (weight) and height of an individual. The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m2, resulting from weight in kilograms and height in meters. If pounds and inches are used, a conversion factor of 703 (kg/m2)/(lb/in2) must be applied. When the term BMI is used informally, the units are usually omitted. A high BMI can be an indicator of high body fatness. BMI can be used as a screening tool but is not diagnostic of the body fatness or health of an individual.

Simply put, BMI is a calculation that uses height and weight measurements to calculate how much body fat a person has. Doctors often use a BMI calculation to determine if a child's weight is appropriate for their height and age. The Child BMI calculator below determines if your child is at a healthy weight for their age (up to 20 years of age), simply enter the required information and calculate their BMI level. You can also check your child's Height to Weight Ratio and Infant Growth Percentile

Adult BMI Calculator

NOTE: For Adult male and female BMI measurements you will need to enter your information into our Body Mass Index Calculator for Adults. In addition you may wish to try our Height to Weight Ratio Chart to measure an average adult's height/weight ratio.

Child Body Mass Index Calculator
Enter the following data
Gender of the child
Age of the child years
BMI (kg per meter square)
BMI percentile
BMI as a multiple of the mean BMI
Automatic recalculation

It is important to have your doctor perform regular BMI measurements for your child so the doctor can discuss the results with you.

The BMI Calculation Formula

Body Mass Index is calculated the same way for both adults and children. The calculation is based on the following formulas:

Measurement Units - Formula and Calculation

Kilograms and Meters or Centimeters

Formula: weight (kg) / [height (m)]2

With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared. Since height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters.

Example: Weight = 68 kg, Height = 165 cm (1.65 m)

Calculation: 68 A- (1.65)2 = 24.98

Pounds and Inches

Formula: weight (lb) / [height (in)]2 x 703

Calculate BMI by dividing weight in pounds (lbs) by height in inches (in) squared and multiplying by a conversion factor of 703.

Example: Weight = 150 lbs, Height = 5'5" (65")

Calculation: [150 A- (65)2] x 703 = 24.96

BMI, Height, and Weight Percentiles

According to the United States CDC National Center for Health Statistics BMI, height, and weight percentiles show how your child compares to other children. For example, if you are 40th percentile in height, that means that you are taller than 40 out of 100 typical children of the same age and sex. If you are 70th percentile in weight that means your child is heavier than 70 out of 100 kids.

BMI Facts

Disabled World also provides a number of informative articles and information relating to Childhood Obesity

📢 Discover Related Topics

👍 Share This Information To:
𝕏.com Facebook Reddit

Page Information, Citing and Disclaimer

Disabled World is an independent disability community founded in 2004 to provide disability news and information to people with disabilities, seniors, their family and/or carers. See our homepage for informative reviews, exclusive stories and how-tos. You can connect with us on social media such as and our Facebook page.

Permalink: <a href="">Child BMI: Body Mass Index Calculator for Children</a>

Cite This Page (APA): Disabled World. (2010, December 27). Child BMI: Body Mass Index Calculator for Children. Disabled World. Retrieved February 21, 2024 from

Disabled World provides general information only. Materials presented are never meant to substitute for qualified professional medical care. Any 3rd party offering or advertising does not constitute an endorsement.