Size Charts for Ugg Australia Footwear
Women's UGG Boot Sizing
| US Size | UK Size | EU Size | Japan Size | CM Size | IN Size |
| 5 | 3.5 | 36 | 22.0 | 22.0 | 8 5/8 |
| 5.5 | 4 | 36.5 | 22.5 | 22.5 | 8 7/8 |
| 6 | 4.5 | 37 | 23.0 | 23.0 | 9 |
| 6.5 | 5 | 37.5 | 23.5 | 23.5 | 9 1/4 |
| 7 | 5.5 | 38 | 24.0 | 24.0 | 9 1/2 |
| 7.5 | 6 | 38.5 | 24.5 | 24.5 | 9 5/8 |
| 8 | 6.5 | 39 | 25.0 | 25.0 | 9 7/8 |
| 8.5 | 7 | 39.5 | 25.5 | 25.5 | 10 |
| 9 | 7.5 | 40 | 26.0 | 26.0 | 10 1/4 |
| 9.5 | 8 | 40.5 | 26.5 | 26.5 | 10 3/8 |
| 10 | 8.5 | 41 | 27.0 | 27.0 | 10 5/8 |
| 10.5 | 9 | 41.5 | 28.0 | 28.0 | 11 |
| 11 | 9.5 | 42 | 28.5 | 28.5 | 11 1/4 |
| 11.5 | 10 | 42.5 | 29.0 | 29.0 | 11 3/8 |
| 12 | 10.5 | 43 | 29.5 | 29.5 | 11 5/8 |
Men's UGG Boot Sizing
| US Size | UK Size | EU Size | Japan Size | CM Size | IN Size |
| 3 | 2 | 34.5 | 21.0 | 21.0 | 8 1/4 |
| 3.5 | 2.5 | 35 | 21.5 | 21.5 | 8 1/2 |
| 4 | 3 | 35.5 | 22.0 | 22.0 | 8 5/8 |
| 4.5 | 3.5 | 36 | 22.5 | 22.5 | 8 7/8 |
| 5 | 4 | 37 | 23.0 | 23.0 | 9 |
| 5.5 | 4.5 | 37.5 | 23.5 | 23.5 | 9 1/4 |
| 6 | 5 | 38 | 24.0 | 24.0 | 9 1/2 |
| 6.5 | 5.5 | 38.5 | 24.5 | 24.5 | 9 5/8 |
| 7 | 6 | 39.5 | 25.0 | 25.0 | 9 7/8 |
| 7.5 | 6.5 | 40 | 25.5 | 25.5 | 10 |
| 8 | 7 | 40.5 | 26.0 | 26.0 | 10 1/4 |
| 8.5 | 7.5 | 41.5 | 26.5 | 26.5 | 10 3/8 |
| 9 | 8 | 42 | 27.0 | 27.0 | 10 5/8 |
| 9.5 | 8.5 | 42.5 | 27.5 | 27.5 | 10 7/8 |
| 10 | 9 | 43 | 28.0 | 28.0 | 11 |
| 10.5 | 9.5 | 44 | 28.5 | 28.5 | 11 1/4 |
| 11 | 10 | 44.5 | 29.0 | 29.0 | 11 3/8 |
| 11.5 | 10.5 | 45 | 29.5 | 29.5 | 11 5/8 |
| 12 | 11 | 45.5 | 30.0 | 30.0 | 11 3/4 |
| 12.5 | 11.5 | 46..5 | 30.5 | 30.5 | 12 |
| 13 | 12 | 47 | 31.0 | 31.0 | 12 1/4 |
| 13.5 | 12.5 | 47.5 | 31.5 | 31.5 | 12 3/8 |
| 14 | 13 | 48.5 | 32.0 | 32.0 | 12 5/8 |
| 14.5 | 13.5 | 49 | 32.5 | 32.5 | 12 3/4 |
| 15 | 14 | 49.5 | 33.0 | 33.0 | 13 |
| 16 | 15 | 50.5 | 33.5 | 33.5 | 13 1/4 |
| 17 | 16 | 51 | 34.0 | 34.0 | 13 3/8 |
| 18 | 17 | 52 | 34.5 | 34.5 | 13 5/8 |
Infants UGG Boot Sizing
| US Size | UK Size | EU Size | Japan Size | CM Size | IN Size |
| 2 & 3 (Small) | 2 | 18 | 13.0 | 13.0 | 5 1/8 |
| 4 & 5 (Medium) | 4 | 20.5 | 14.0 | 14.0 | 5 1/2 |
| 6 | 5 | 22.5 | 14.5 | 14.5 | 5 3/4 |
| 7 | 6 | 23.5 | 15.0 | 15.0 | 5 7/8 |
| 8 | 7 | 25 | 15.5 | 15.5 | 6 1/8 |
| 9 | 8 | 26 | 16.0 | 16.0 | 6 1/4 |
Little Kids UGG Boot Sizing
| US Size | UK Size | EU Size | Japan Size | CM Size | IN Size |
| 6 | 5 | 22.5 | 14.5 | 14.5 | 5 3/4 |
| 7 | 6 | 23.5 | 14.8 | 14.8 | 5 7/8 |
| 8 | 7 | 25 | 15.0 | 15.0 | 5 7/8 |
| 8.5 | 7.5 | 25.5 | 15.5 | 15.5 | 6 1/8 |
| 9 | 8 | 26 | 16.0 | 16.0 | 6 1/4 |
| 9.5 | 8.5 | 26.5 | 16.3 | 16.3 | 6 3/8 |
| 10 | 9 | 27 | 16.5 | 16.5 | 6 1/2 |
| 10.5 | 9.5 | 27.5 | 16.8 | 16.8 | 6 5/8 |
| 11 | 10 | 28 | 17.0 | 17.0 | 6 3/4 |
| 11.5 | 10.5 | 28.5 | 17.2 | 17.2 | 6 3/4 |
| 12 | 11 | 29 | 17.5 | 17.5 | 6 7/8 |
| 12.5 | 11.5 | 29.5 | 17.8 | 17.8 | 7 |
| 13 | 12 | 30 | 18.0 | 18.0 | 7 1/8 |
| 13.5 | 12.5 | 30.5 | 18.5 | 18.5 | 7 1/4 |
Big Kids UGG Boot Sizing
| US Size | UK Size | EU Size | Japan Size | CM Size | IN Size |
| 1 | 13 | 31 | 19.0 | 19.0 | 7 1/2 |
| 1.5 | 13.5 | 31.5 | 19.5 | 19.5 | 7 5/8 |
| 2 | 1 | 32 | 20.0 | 20.0 | 7 7/8 |
| 2.5 | 1.5 | 32.5 | 20.5 | 20.5 | 8 1/8 |
| 3 | 2 | 33 | 20.8 | 20.8 | 8 1/4 |
| 3.5 | 2.5 | 33.5 | 21.0 | 21.0 | 8 1/4 |
| 4 | 3 | 34 | 21.5 | 21.5 | 8 1/2 |
| 4.5 | 3.5 | 34.5 | 21.8 | 21.8 | 8 5/8 |
| 5 | 4 | 35 | 22.0 | 22.0 | 8 5/8 |
| 5.5 | 4.5 | 35.5 | 22.3 | 22.3 | 8 3/4 |
| 6Y | 5 | 36 | 22.5 | 22.5 | 8 7/8 |