Weight for boys at 12 years
At 12 years, the median weight for boys on the CDC 2000 growth charts is 40.5 kg (89 lb 4 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 35.7 and 46.6 kg, a spread of 10.9 kg. The outer lines of the chart, the 3rd and 97th percentiles, sit at 29.3 and 63.0 kg.
Since 11 years, the median has risen by 4.58 kg over 1 year. By 13 years it reaches 45.6 kg.
For girls at 12 years the median is 41.6 kg, 1.17 kg more 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 12 years who weighs 44.1 kg is at about the 66th percentile, meaning that out of 100 boys this age, about 66 weigh less.
Percentiles at 12 years
Download CSV (all ages)| Percentile | z-score | Metric | Imperial |
|---|---|---|---|
| 3rd | −1.88 | 29.34 kg | 64 lb 11 oz |
| 5th | −1.64 | 30.41 kg | 67 lb 1 oz |
| 10th | −1.28 | 32.21 kg | 71 lb 0 oz |
| 25th | −0.67 | 35.69 kg | 78 lb 11 oz |
| 50th (median) | 0.00 | 40.47 kg | 89 lb 4 oz |
| 75th | +0.67 | 46.58 kg | 102 lb 11 oz |
| 90th | +1.28 | 53.71 kg | 118 lb 7 oz |
| 95th | +1.64 | 59.02 kg | 130 lb 2 oz |
| 97th | +1.88 | 63.01 kg | 138 lb 15 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).