At ages 10 and 11, boys' and girls' top swimming standards differ by under 2%. From age 12 the boys' standards pull ahead every year, reaching about 12% faster by age 18.
| age | events | free100ScyGapPct | free500ScyGapPct | free50ScyGapPct | maxGapPct | medianGapPct | minGapPct |
|---|---|---|---|---|---|---|---|
| 10 | 35 | 1.3 | 2.5 | 2.9 | 2.9 | 1.6 | 0.6 |
| 11 | 53 | 2.1 | 1.7 | 1.9 | 2.6 | 1.4 | 0 |
| 12 | 53 | 4.5 | 4.1 | 4.9 | 5.5 | 4.2 | 1.4 |
| 13 | 51 | 7.3 | 5.5 | 7.3 | 7.9 | 6.3 | 4.6 |
| 14 | 51 | 9.2 | 6.8 | 9.4 | 10.2 | 8.4 | 5.4 |
| 15 | 51 | 10.7 | 8.4 | 11.5 | 11.7 | 9.3 | 5.4 |
| 16 | 51 | 11.1 | 8.7 | 12.2 | 12.5 | 10.3 | 6.5 |
| 17 | 51 | 12.2 | 9.4 | 12.8 | 14.1 | 10.9 | 6.9 |
| 18 | 51 | 12.8 | 9.1 | 14.5 | 14.6 | 12.1 | 7.7 |