Baby Growth Percentile Calculator – Calculate Weight & Height Percentile

Calculate your baby’s weight, height, and head circumference percentiles for their age group.


Weight Percentile:

This calculation is based on CDC growth chart percentile data,[1] but it is not a prescription for your child's health and nutrition. Consult with your doctor before making a change to your child's nutrition or diet
Learn how we calculated this below

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How to Find Baby Weight and Height Percentiles

In order to monitor the healthy growth of your baby, weight and height percentile charts have been developed.[4] Height in infants is actually termed “length” since they do not stand upright.

In infants, growth is charted based on measuring length for age and weight for age. These graphs are also different between boys and girls as they grow at a slightly different rate.

The growth charts for infants are different than the height, weight, and BMI charts used for children.

Baby weight percentile

To determine what percentile your baby falls into, you simply find the age of your infant on the x-axis and then by matching this up with the weight (in either pounds or kilograms) on the y-axis, you can see what percentile this corresponds to.

You can also use a baby weight percentile calculator above and type in their age and weight values to calculate the percentile.

For example, if you have a six-week-old boy that weighs 12.5 pounds, this puts them in the 50th percentile for their weight. This means 50% of babies weigh more, and 50% of babies weigh less. This puts them at an average weight for their age.

Baby height percentile

Just like you do with the weight percentile, you use this same method to chart out your infant’s height, or length, percentile. Your baby’s length is measured from the top of their head to the bottom of one of their heels.

For instance, if your six-week-old baby boy is 22 ¼ inches long, they fall into the 48th percentile for length. This means 48% of babies are shorter, while 52% of babies are longer. This puts them at about an average length for age and suggests normal development.

This data can also be compared to numeric charts to get exact weight and height percentile data.


  1. Centers for Disease Control and Prevention, Data Table of Infant Weight-for-age Charts,
  2. Centers for Disease Control and Prevention, Data Table of Infant Length-for-age Charts,
  3. Centers for Disease Control and Prevention, Data Table of Infant Head Circumference-for-age Charts,
  4. Centers for Disease Control and Prevention, Clinical Growth Charts, June 16, 2017,