On vs Ugg shoe sizing
Compare On and Ugg shoe sizes in EU, US and UK. Use this chart to see size differences and check whether On or Ugg runs smaller or larger.
Choose your size to see the result.
| On (EU) | Ugg (EU) | Baseline (CM) |
|---|---|---|
| 39 | 39 | 24 |
| 39.5 | 39 | 24.5 |
| 40 | 39 | 25 |
| 40.5 | 40 | 25.5 |
| 41 | 40.5 | 26 |
| 42 | 41 | 26.5 |
| 42.5 | 42 | 27 |
| 43 | 42.5 | 27.5 |
| 44 | 43 | 28 |
| 44.5 | 44 | 28.5 |
| 45 | 44.5 | 29 |
| 46 | 45 | 29.5 |
| 47 | 46 | 30 |
| 48.5 | 47 | 31 |
| 50 | 48 | 32 |
| 51.5 | 49 | 33 |
FAQ
How do I convert On to Ugg?
Use the converter above. We map sizes via official chart baselines (cm/EU) when available.
Do these brands run small or large?
Based on official charts, Ugg EU labels are typically -0.8 compared to On for similar foot length (cm). Real fit can vary by model.
What if I’m between sizes?
If you prefer a snug fit, lean down; for extra room, lean up - and always check the brand’s model-specific guidance.