What percentile is she on? Plot it and see.
Add your baby’s birth date and a measurement or two. This free WHO growth chart calculator draws them on the World Health Organization’s baby growth charts for girls or boys, from birth to five years, and shows the percentile for each.
Plot a measurement
Source: WHO Child Growth Standards, birth to 60 months, 3rd to 97th percentile.
Born early? The chart counts from the birth date you enter, with no correction. Pediatricians often use a corrected age for a baby born early, so if their chart and this one don’t match, go by theirs.
What you’ll see
- Five curves. The 3rd, 15th, 50th, 85th and 97th percentiles. The 50th is the solid one, and your baby’s line runs over them.
- A percentile for every measurement, in a table under the chart with the date and her age in months. Below the 3rd or above the 97th you still get a number, but it’s an estimate, because those are the outermost curves.
What does a percentile mean on a growth chart?
A percentile says where one measurement sits among children of the same age and sex in the WHO reference.
Picture a hundred girls her age from that reference, lined up. On the 50th percentile for weight, she’s heavier than half of them and lighter than the other half. On the 10th, she’s heavier than ten of them. Boys are compared with boys, the same way.
So it isn’t a mark out of a hundred, and the 50th isn’t a pass mark. It’s the middle. Half of all healthy children sit below it, and healthy children can be on any percentile.
One reading can also move for ordinary reasons. She’s compared with other children, who are growing too, and measuring a wriggly baby exactly is hard. Two people can get lengths a centimeter apart, minutes apart.
How each measurement is taken
The WHO charts were built from measurements taken a certain way, so it helps to take yours the same way.
- Weight is naked, or dressed with the clothes weighed and taken off. A full diaper is about a hundred grams, and a feed weighs more. The same scale at the same time of day beats a fancy scale at random times.
- Length, under two, is taken lying down, head against something firm and legs straight. It takes two people, so a length taken at home is the hardest to get right.
- Height, from two, is taken standing, heels and back against a wall, looking straight ahead. The same child reads about 0.7 cm shorter standing than lying down, so the WHO has a separate table for each.
- Head circumference is the widest way round: above the eyebrows and ears, and around the back where the head sticks out most. Pull a soft tape snug, take it two or three times, and write down the largest.
Is this the WHO chart or the CDC chart?
It’s the WHO Child Growth Standards, birth to 60 months, with separate tables for girls and boys. The WHO published them in 2006 from the Multicentre Growth Reference Study, which followed healthy, breastfed children growing up in good conditions in Brazil, Ghana, India, Norway, Oman and the United States.
The CDC charts are the other set a US parent meets. They come from national surveys and show how American children measured. The CDC itself recommends the WHO charts from birth to 24 months and its own from two to twenty years. So for a baby under two, this is the chart a US pediatrician uses too.
After two, they switch to the CDC charts, which were drawn from different children and give different numbers. If this page and theirs don’t match for an older child, that’s why.
Prefer the tables?
- Baby weight chart by month. Weight, birth to five years, in kilograms and pounds.
- Baby height chart by month. Length and height, in centimeters and inches.
- Baby head circumference chart. Head circumference, in centimeters and inches.
Other free tools here
- Baby age calculator. Her age in days, weeks and months, plus corrected age for a baby born early.
- Baby weight converter. Kilograms to pounds and ounces, centimeters to inches.
- Diaper size calculator. Which sizes fit your baby’s weight.
- Formula amount calculator. What the AAP and NHS guidelines say for a weight, with the sources.
Questions about growth charts
Why does the growth chart stop at five years?
Because the WHO standards stop at 60 months. After five, growth is followed on a different reference (in the US, the CDC charts for two to twenty), and your pediatrician will already be using it.
Do I need an account to use the growth chart calculator?
No. The calculator runs in your browser: nothing’s uploaded, nothing’s stored, no sign-up. The app is where you keep the history and get the pediatrician report, but the chart itself is free for anyone.
Keeping these by hand gets old. Bundle of Joy charts weight, height and head circumference as you log them, and makes a PDF for the appointment.
Every measurement, on one chart.
Weight, height and head circumference on the WHO charts.
