Weight for boys at 4 years
At 4 years, the median weight for boys on the CDC 2000 growth charts is 16.2 kg (35 lb 13 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 15.0 and 17.6 kg, a spread of 2.63 kg. The outer lines of the chart, the 3rd and 97th percentiles, sit at 13.2 and 20.9 kg.
Since 3 years, the median has risen by 1.90 kg over 1 year. By 5 years it reaches 18.4 kg.
For girls at 4 years the median is 15.8 kg, 0.44 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 4 years who weighs 17.1 kg is at about the 66th percentile, meaning that out of 100 boys this age, about 66 weigh less.
Percentiles at 4 years
Download CSV (all ages)| Percentile | z-score | Metric | Imperial |
|---|---|---|---|
| 3rd | −1.88 | 13.23 kg | 29 lb 3 oz |
| 5th | −1.64 | 13.54 kg | 29 lb 14 oz |
| 10th | −1.28 | 14.06 kg | 31 lb 0 oz |
| 25th | −0.67 | 15.02 kg | 33 lb 2 oz |
| 50th (median) | 0.00 | 16.23 kg | 35 lb 13 oz |
| 75th | +0.67 | 17.65 kg | 38 lb 15 oz |
| 90th | +1.28 | 19.14 kg | 42 lb 3 oz |
| 95th | +1.64 | 20.16 kg | 44 lb 7 oz |
| 97th | +1.88 | 20.87 kg | 46 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).