HeightPredictorChild height calculator · based on parents
How tall will your child be?
Your heights, their age and height today. You get their adult height and their percentile on the CDC growth chart. A height calculator for ages 2 to 12, built on the same references pediatricians use.
How it works
The same eight questions, asked about your child: their birth month, height today, both your heights, and their sleep, activity and food. Under the hood it is a mid-parental height calculator (the average of both parents, adjusted for sex) combined with a growth-curve projection against CDC and WHO references.
That combination is close to the Khamis-Roche method clinics use when no bone X-ray is available. It is a genetic height calculator on one side and a growth-curve reading on the other, and the result is a range with a most-likely number inside it.
Height percentile calculator on the CDC growth chart
A percentile says how your child compares with children of the same age and sex. A boy of 8 at 50 inches (127 cm) is right on the median, the 50th percentile. At 53 inches he is near the 85th. That is what a growth percentile calculator reports, and it is the number your pediatrician plots at each visit.
Percentile is not a grade. A child who tracks the 25th line year after year is growing normally. What matters is the curve staying on its line. A growth chart calculator that shows only today's percentile misses that, so the result also shows the projected adult height on the same chart.
How tall will my son be? How tall will my daughter be?
The mid-parental formula is the same for both, with one difference: for a son, add 2.5 inches (6.5 cm) to the mother's height before averaging; for a daughter, subtract 2.5 inches from the father's. Boys also keep growing about two years longer, so a boy's percentile at 12 can still shift more than a girl's.
"How tall will my son be?" is the most common question we get from parents. The honest answer is a range about 4 inches (10 cm) wide at age 8, narrowing to about 2 inches by 14.
Ages 2 to 12 here. 13 or older? Take the predictor.
This page is a height calculator for kids, asked in your words about your child. From 13 the growth spurt makes the curve personal, so a height calculator for teens should be answered by the teen.
People also ask
What is the mid-parental height formula?
For a boy: (mother's height + 2.5 in + father's height) ÷ 2. For a girl: (father's height − 2.5 in + mother's height) ÷ 2. The result is the genetic target; most children land within about 4 inches (10 cm) of it. The height calculator formula here adds the child's own growth curve on top, which tightens the range.
How accurate is a child height calculator?
Mid-parental height alone is right to within about 4 inches for 95 percent of children. Adding the child's current height and age against the CDC growth chart roughly halves that. Illness, nutrition and timing of puberty explain most of what remains.
What does a height percentile mean?
The share of children of the same age and sex who are shorter. The 50th percentile is the median. Between the 5th and 95th is the normal range on the CDC growth chart; outside it, a pediatrician usually takes a closer look.
What is a bone age calculator, and do I need one?
A bone age reading comes from an X-ray of the hand and tells how mature the growth plates are. It is the most precise input for adult height, but it needs a clinic. This calculator uses age, height and parent heights instead, which is what the Khamis-Roche method does without an X-ray.
Is this the same as a growth percentile calculator?
It includes one. A growth percentile calculator gives you today's position on the chart; this result adds the projected adult height and how much of the remaining growth sleep, movement and food can still move.
When do boys and girls stop growing?
Girls usually stop between 15 and 16, boys between 17 and 18, when the growth plates close. Early or late puberty shifts those ages by a year or two either way.