Height for boys at 9 years
At 9 years, the median height for boys on the CDC 2000 growth charts is 133.5 cm (52.6 in): half of boys this age measure less and half more. The middle half of boys, from the 25th to the 75th percentile, falls between 129.4 and 137.7 cm, a spread of 8.3 cm. The outer lines of the chart, the 3rd and 97th percentiles, sit at 122.2 and 145.4 cm.
Since 8 years, the median has risen by 5.6 cm over 1 year. By 10 years it reaches 138.6 cm.
For girls at 9 years the median is 132.9 cm, 0.6 cm less than for boys, which is why the charts are drawn separately by sex.
From 2 years CDC recommends its own 2000 growth charts, which draw the 3rd to the 97th percentile; under 2, the WHO charts draw the 2nd to the 98th.
Reading the table: a boy at 9 years who measures 136.0 cm is at about the 66th percentile, meaning that out of 100 boys this age, about 66 measure less. From 2 years this is height measured standing. If a child of 2 or older was measured lying down, CDC subtracts 0.8 cm before comparing.
Percentiles at 9 years
Download CSV (all ages)| Percentile | z-score | Metric | Imperial |
|---|---|---|---|
| 3rd | −1.88 | 122.2 cm | 48.1 in |
| 5th | −1.64 | 123.6 cm | 48.7 in |
| 10th | −1.28 | 125.7 cm | 49.5 in |
| 25th | −0.67 | 129.4 cm | 50.9 in |
| 50th (median) | 0.00 | 133.5 cm | 52.6 in |
| 75th | +0.67 | 137.7 cm | 54.2 in |
| 90th | +1.28 | 141.5 cm | 55.7 in |
| 95th | +1.64 | 143.9 cm | 56.6 in |
| 97th | +1.88 | 145.4 cm | 57.2 in |
CDC 2000 charts draw the 3rd to the 97th percentile. Values computed with the LMS method from the published tables (retrieved 2026-10-05).