Weight for boys at 8 years
At 8 years, the median weight for boys on the CDC 2000 growth charts is 25.6 kg (56 lb 8 oz): half of boys this age weigh less and half more. The middle half of boys, from the 25th to the 75th percentile, falls between 23.2 and 28.7 kg, a spread of 5.47 kg. The outer lines of the chart, the 3rd and 97th percentiles, sit at 20.0 and 37.2 kg.
Since 7 years, the median has risen by 2.57 kg over 1 year. By 9 years it reaches 28.6 kg.
For girls at 8 years the median is 25.6 kg, 0.01 kg 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 8 years who weighs 27.5 kg is at about the 67th percentile, meaning that out of 100 boys this age, about 67 weigh less.
Percentiles at 8 years
Download CSV (all ages)| Percentile | z-score | Metric | Imperial |
|---|---|---|---|
| 3rd | −1.88 | 20.04 kg | 44 lb 3 oz |
| 5th | −1.64 | 20.58 kg | 45 lb 6 oz |
| 10th | −1.28 | 21.49 kg | 47 lb 6 oz |
| 25th | −0.67 | 23.24 kg | 51 lb 4 oz |
| 50th (median) | 0.00 | 25.64 kg | 56 lb 8 oz |
| 75th | +0.67 | 28.71 kg | 63 lb 5 oz |
| 90th | +1.28 | 32.34 kg | 71 lb 5 oz |
| 95th | +1.64 | 35.09 kg | 77 lb 6 oz |
| 97th | +1.88 | 37.20 kg | 82 lb 0 oz |
CDC 2000 charts draw the 3rd to the 97th percentile. Values computed with the LMS method from the published tables (retrieved 2026-10-05).