On the WHO child growth standards, the median height is about 75cm (29.5 inches) at 1 year, 87cm (34 inches) at 2, 96cm (38 inches) at 3, 103cm (40.5 inches) at 4 and 110cm (43 inches) at 5. Boys run about 0.6 to 1.7cm taller than girls at each age. Healthy children fall well above and below these medians.
Average height by age: boys and girls, 1 to 5
The table shows the WHO median and the 3rd and 97th percentiles, which together span the heights of 94 in every 100 children on the standard. Ages 1 and 1.5 use lying-down length; ages 2 to 5 use standing height.
| Age | Boys: 3rd | Boys: median | Boys: 97th | Girls: 3rd | Girls: median | Girls: 97th |
|---|---|---|---|---|---|---|
| 12 months | 71.3cm | 75.7cm | 80.2cm | 69.2cm | 74.0cm | 78.9cm |
| 18 months | 77.2cm | 82.3cm | 87.3cm | 75.2cm | 80.7cm | 86.2cm |
| 2 years | 81.4cm | 87.1cm | 92.9cm | 79.6cm | 85.7cm | 91.8cm |
| 3 years | 89.1cm | 96.1cm | 103.1cm | 87.9cm | 95.1cm | 102.2cm |
| 4 years | 95.4cm | 103.3cm | 111.2cm | 94.6cm | 102.7cm | 110.8cm |
| 5 years | 101.2cm | 110.0cm | 118.7cm | 100.5cm | 109.4cm | 118.4cm |
In inches, the medians are 29.8 (boys) and 29.1 (girls) at 12 months, 32.4 and 31.8 at 18 months, 34.3 and 33.7 at 2, 37.8 and 37.4 at 3, 40.7 and 40.4 at 4, and 43.3 and 43.1 at 5.
| Name | Height |
|---|---|
| Boy, 2 (median) | 87.1 cm |
| Girl, 5 (median) | 109.4 cm |
| Boy, 5 (median) | 110 cm |
| UK average woman | 163.9 cm |
How fast do toddlers grow?
Growth is fastest in the first year and slows steadily through the preschool years. Using the medians above, the typical yearly gain falls from about 12cm between 1 and 2 to about 7cm between 4 and 5.
| Between ages | Boys gain (median) | Girls gain (median) |
|---|---|---|
| 1 and 2 | 12.1cm | 12.4cm |
| 2 and 3 | 9.0cm | 9.4cm |
| 3 and 4 | 7.2cm | 7.6cm |
| 4 and 5 | 6.7cm | 6.7cm |
The 1-to-2 gain compares lying-down length at both ages (75.7cm to 87.8cm for boys, 74.0cm to 86.4cm for girls), so it is not distorted by the change in measuring method. The later rows use standing height.
A child who gains 5 to 6cm in a year at age 4 is not necessarily slowing down: the median is 7cm and healthy children vary around it. What clinicians look at is whether a child keeps to a similar percentile line over several measurements.
Length or height: why the method matters
Until a child is two, they are measured lying flat on a measuring board. From two, they stand. Lying-down measurements read slightly higher. On the WHO standard the difference at 24 months is 0.7cm for both sexes: median length 87.8cm and median standing height 87.1cm for boys, 86.4cm and 85.7cm for girls.
This means a child measured on their second birthday can appear to “lose” 0.7cm if the method changes. It is a feature of the measurement, not of the child. The same effect is behind the small step in many growth charts at age 2.
What the WHO standard is, and is not
The WHO child growth standards describe how children grow when they have good nutrition, healthcare and a healthy environment. The WHO calls this a standard because it states how children should grow in those conditions, in contrast to a reference that simply describes a particular population. It was built from a multi-country study of healthy breastfed children, so the same standard is used worldwide. In the UK, the growth charts in a child’s personal child health record are based on the WHO standards.
The standard is useful for spotting a change in pattern. It is not a pass mark. A child whose parents are both short will often track low on the chart, and a child with tall parents will track high. Both can be completely healthy.
Boys versus girls
The medians show a small but steady gap. Boys are about 1.7cm taller at 12 months, 1.4cm at 2, 1.0cm at 3, 0.6cm at 4 and 0.6cm at 5. The gap is small compared with the variation between children of the same sex, which is why a girl can easily be taller than a boy of the same age.
By the teenage years boys pull clearly ahead. For the later ages, see average height for a 10-year-old and average height for teenagers.
Should I worry about my toddler’s height?
Most children who look small or tall are following a healthy pattern set by their parents’ heights. It is worth speaking to a GP, health visitor or paediatrician if your child’s measurements fall across several percentile lines, if growth seems to have stalled, or if you simply have a concern. This article is a reference, not medical advice.
For a rough idea of eventual adult height, the child height predictor uses the parents’ heights, and how tall will my child be compares four methods. To place an older child on the chart, use the percentile calculator.
How these figures were calculated
The 3rd percentile, median (50th) and 97th percentile values are taken directly from the WHO Child Growth Standards percentile tables linked above: length-for-age for 0 to 2 years and height-for-age for 2 to 5 years, separate tables for boys and girls. Inch values divide centimetres by 2.54. Yearly gains are differences between consecutive medians, using length at both ages for 1 to 2 years. Last reviewed 25 October 2026.
Open the comparison board to stand a 5-year-old next to a parent, or use the height converter to switch any figure between centimetres and inches.