📏Baby Height (Length) Percentile (2026)
A baby height (length, for babies measured lying down) percentile compares your baby's length to other babies of the same age and sex. The 50th percentile is the median — half of babies are taller, half shorter. Tall and short babies can be equally healthy. Genetics plays a huge role: tall parents tend to have babies on the higher curves.
How to read it
Length in babies is tricky to measure accurately — a wiggly newborn can read a centimeter off. Doctors look at the trend over several visits. Babies typically gain about 2.5 cm/month in the first 6 months, then 1.25 cm/month from 6-12 months.
Average length by age (reference, 50th percentile)
| Age | Boys (50th) | Girls (50th) |
|---|---|---|
| Newborn (0 months) | 19.6 in · 49.9 cm | 19.3 in · 49.1 cm |
| 6 months | 26.6 in · 67.6 cm | 25.9 in · 65.7 cm |
| 12 months | 29.8 in · 75.7 cm | 29.1 in · 74.0 cm |
| 18 months | 32.4 in · 82.3 cm | 31.8 in · 80.7 cm |
| 24 months | 34.6 in · 87.8 cm | 34.0 in · 86.4 cm |
Length shown in cm and inches. Babies under 24 months are measured lying down (recumbent length), which reads slightly longer than standing height. See full month-by-month tables on each age page.
Frequently asked questions
What is a baby height percentile?
A baby height (length, for babies measured lying down) percentile compares your baby's length to other babies of the same age and sex. The 50th percentile is the median — half of babies are taller, half shorter. Tall and short babies can be equally healthy. Genetics plays a huge role: tall parents tend to have babies on the higher curves.
Is a high or low baby height percentile a problem?
Not by itself. Length in babies is tricky to measure accurately — a wiggly newborn can read a centimeter off. Doctors look at the trend over several visits. Babies typically gain about 2.5 cm/month in the first 6 months, then 1.25 cm/month from 6-12 months. BabyPercent is educational only, not medical advice — your pediatrician is the right person to interpret any measurement.
How is baby height percentile measured?
Length shown in cm and inches. Babies under 24 months are measured lying down (recumbent length), which reads slightly longer than standing height.
WHO vs CDC: which chart should I use?
The WHO charts are recommended by the CDC and AAP for ages 0-24 months. They are based on healthy, breastfed babies from six countries. CDC charts represent a US reference population. BabyPercent provides both so you can compare — your pediatrician probably uses WHO for babies under 2.
How often should my baby be weighed and measured?
The AAP recommends well-baby visits at 3-5 days, 1 month, 2 months, 4 months, 6 months, 9 months, 12 months, 15 months, 18 months, and 24 months. At each visit, your pediatrician measures weight, length, and head circumference. Avoid weighing at home daily — weekly or monthly is plenty.
What is catch-up growth?
Catch-up growth is faster-than-average growth that happens when a baby recovers from a period of slower growth — for example, after an illness or after a premature baby adjusts to life outside the womb. It is a normal compensatory mechanism. Your pediatrician watches for it and will tell you if it is happening as expected.
Does birth weight predict future size?
Not reliably. Birth weight is heavily influenced by in-utero factors like maternal nutrition, gestational age, and placental function. By age 2, a child's growth tends to align more with their genetic potential (parental heights). A small newborn can become a tall adult, and a large newborn can settle into a lower percentile by toddlerhood.
Can growth charts predict my child's adult height?
Roughly, yes — doubling a child's height at 24 months gives a ballpark estimate of adult height, but this is imprecise. Genetics, nutrition, and health all influence final height. Growth charts track the journey, not the destination.