Baby boy length (height) chart by month
WHO length-for-age percentiles for baby boys at every month from birth to 24 months, in cm and in inches. Use the calculator to find your son’s length percentile for their exact age. For girls, see the baby girl length (height) chart by month.
Enter a date of birth and at least one measurement to see the percentile.
Key numbers
- The WHO median birth length for boys is 49.9 cm (19.6 in); the 3rd to 97th percentile at birth runs from 46.3 cm (18.2 in) to 53.4 cm (21.0 in).
- The median is 61.4 cm (24.2 in) at 3 months, 67.6 cm (26.6 in) at 6 months, 72.0 cm (28.3 in) at 9 months and 75.7 cm (29.8 in) at 12 months.
- Median length grows about 26 cm in the first year, nearly half of it in the first 3 months.
- At 2 years the median is 87.8 cm (34.6 in). Length is measured lying down until age 2; after that, standing height is used.
Baby boy length by month in cm (WHO)
Length in cm at each percentile. The median (50th) is the average length for that age.
| Age | 3th | 15th | Median | 85th | 97th |
|---|---|---|---|---|---|
| Birth | 46.3 | 47.9 | 49.9 | 51.8 | 53.4 |
| 1 month | 51.1 | 52.7 | 54.7 | 56.7 | 58.4 |
| 2 months | 54.7 | 56.4 | 58.4 | 60.5 | 62.2 |
| 3 months | 57.6 | 59.3 | 61.4 | 63.5 | 65.3 |
| 4 months | 60.0 | 61.7 | 63.9 | 66.0 | 67.8 |
| 5 months | 61.9 | 63.7 | 65.9 | 68.1 | 69.9 |
| 6 months | 63.6 | 65.4 | 67.6 | 69.8 | 71.6 |
| 7 months | 65.1 | 66.9 | 69.2 | 71.4 | 73.2 |
| 8 months | 66.5 | 68.3 | 70.6 | 72.9 | 74.7 |
| 9 months | 67.7 | 69.6 | 72.0 | 74.3 | 76.2 |
| 10 months | 69.0 | 70.9 | 73.3 | 75.6 | 77.6 |
| 11 months | 70.2 | 72.1 | 74.5 | 77.0 | 78.9 |
| 12 months | 71.3 | 73.3 | 75.7 | 78.2 | 80.2 |
| 13 months | 72.3 | 74.4 | 76.9 | 79.4 | 81.5 |
| 14 months | 73.4 | 75.5 | 78.0 | 80.6 | 82.7 |
| 15 months | 74.4 | 76.5 | 79.1 | 81.8 | 83.9 |
| 16 months | 75.3 | 77.5 | 80.2 | 82.9 | 85.1 |
| 17 months | 76.2 | 78.5 | 81.2 | 84.0 | 86.3 |
| 18 months | 77.1 | 79.4 | 82.3 | 85.1 | 87.4 |
| 19 months | 78.0 | 80.4 | 83.2 | 86.1 | 88.5 |
| 20 months | 78.8 | 81.2 | 84.2 | 87.2 | 89.6 |
| 21 months | 79.7 | 82.1 | 85.1 | 88.2 | 90.6 |
| 22 months | 80.5 | 83.0 | 86.0 | 89.1 | 91.6 |
| 23 months | 81.2 | 83.8 | 86.9 | 90.1 | 92.7 |
| 24 months | 82.0 | 84.6 | 87.8 | 91.0 | 93.6 |
Baby boy length by month in inches (WHO)
Length in in at each percentile. The median (50th) is the average length for that age.
| Age | 3th | 15th | Median | 85th | 97th |
|---|---|---|---|---|---|
| Birth | 18.2 | 18.9 | 19.6 | 20.4 | 21.0 |
| 1 month | 20.1 | 20.8 | 21.5 | 22.3 | 23.0 |
| 2 months | 21.5 | 22.2 | 23.0 | 23.8 | 24.5 |
| 3 months | 22.7 | 23.4 | 24.2 | 25.0 | 25.7 |
| 4 months | 23.6 | 24.3 | 25.2 | 26.0 | 26.7 |
| 5 months | 24.4 | 25.1 | 25.9 | 26.8 | 27.5 |
| 6 months | 25.0 | 25.8 | 26.6 | 27.5 | 28.2 |
| 7 months | 25.6 | 26.3 | 27.2 | 28.1 | 28.8 |
| 8 months | 26.2 | 26.9 | 27.8 | 28.7 | 29.4 |
| 9 months | 26.7 | 27.4 | 28.3 | 29.2 | 30.0 |
| 10 months | 27.2 | 27.9 | 28.9 | 29.8 | 30.5 |
| 11 months | 27.6 | 28.4 | 29.3 | 30.3 | 31.1 |
| 12 months | 28.1 | 28.9 | 29.8 | 30.8 | 31.6 |
| 13 months | 28.5 | 29.3 | 30.3 | 31.3 | 32.1 |
| 14 months | 28.9 | 29.7 | 30.7 | 31.7 | 32.6 |
| 15 months | 29.3 | 30.1 | 31.2 | 32.2 | 33.0 |
| 16 months | 29.7 | 30.5 | 31.6 | 32.6 | 33.5 |
| 17 months | 30.0 | 30.9 | 32.0 | 33.1 | 34.0 |
| 18 months | 30.4 | 31.3 | 32.4 | 33.5 | 34.4 |
| 19 months | 30.7 | 31.6 | 32.8 | 33.9 | 34.8 |
| 20 months | 31.0 | 32.0 | 33.1 | 34.3 | 35.3 |
| 21 months | 31.4 | 32.3 | 33.5 | 34.7 | 35.7 |
| 22 months | 31.7 | 32.7 | 33.9 | 35.1 | 36.1 |
| 23 months | 32.0 | 33.0 | 34.2 | 35.5 | 36.5 |
| 24 months | 32.3 | 33.3 | 34.6 | 35.8 | 36.9 |
How to read this chart
A percentile compares your baby’s length with other boys of the same age. At the 50th percentile, half of healthy boys measure more and half measure less. Anything between the 3rd and the 97th percentile is within the usual range on the WHO chart.
The trend matters more than one number. A baby who stays near the same percentile line from visit to visit is growing steadily, whether that line is the 15th or the 85th. More in What percentile should my baby be?
Common questions
What is the average length (height) of a baby boy by month?
The WHO median, the usual "average", is 54.7 cm (21.5 in) at 1 month, 58.4 cm (23.0 in) at 2 months, 61.4 cm (24.2 in) at 3 months, 63.9 cm (25.2 in) at 4 months, 67.6 cm (26.6 in) at 6 months, 70.6 cm (27.8 in) at 8 months, 72.0 cm (28.3 in) at 9 months, 75.7 cm (29.8 in) at 12 months, 82.3 cm (32.4 in) at 18 months. The table on this page lists every month to 24 months.
What is a normal length for a newborn baby boy?
On the WHO standard, the 3rd to 97th percentile at birth for boys runs from 46.3 cm (18.2 in) to 53.4 cm (21.0 in), with a median of 49.9 cm (19.6 in).
What is a normal height for an 8-month-old boy?
On the WHO standard, the 3rd to 97th percentile at 8 months runs from 66.5 cm (26.2 in) to 74.7 cm (29.4 in), with a median of 70.6 cm (27.8 in).
How tall is a 1-year-old boy on average?
The WHO median at 12 months is 75.7 cm (29.8 in); the 3rd to 97th percentile runs from 71.3 cm (28.1 in) to 80.2 cm (31.6 in).
Should I use the WHO or the CDC chart?
The CDC recommends the WHO growth charts for children under 2 years in the United States, and the CDC charts from age 2. Values on this page are from the WHO Child Growth Standards.
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Start tracking freeAlso: baby length chart for girls and boys · baby boy weight chart · growth chart calculator for boys
Source: WHO Child Growth Standards, length/height-for-age, percentiles computed from the WHO LMS tables at each whole month. For information only; not medical advice.