UGG sizing confuses people for one reason: the sheepskin. A new UGG feels tighter than a sneaker in the same size, then loosens by about half a size as the lining compresses to your foot. Buy for the second week, not the first day. Here is how that plays out model by model.
The short answer
- UGGs run true to size, in whole sizes only.
- If you wear a half size, go down for the Classic boots, Tasman, Tazz and Coquette. The sheepskin gives you the half size back.
- If the lining is UGGplush (wool blend, as on the Neumel and Lowmel), there is less stretch: go up if you are between sizes or want room for thick socks.
- Snug at first is correct. Your toes should reach near the end without curling; heel and midfoot should feel held.
How the fit changes
The first week, a new Classic Mini or Tasman feels close all round. After ten to fifteen wears the sheepskin underfoot packs down and the footbed takes the shape of your foot, which adds volume. A boot that felt comfortable on day one usually feels loose by month two; a boot that felt snug on day one feels right. That is why UGG's own advice is to size down rather than up.
Model by model
| Model | Lining | Fit | If you are a half size |
|---|---|---|---|
| Classic Mini II, Ultra Mini, Classic Short II | Sheepskin | True to size, snug | Go down |
| Tasman, Tazz, Coquette, Disquette | Sheepskin | True to size, snug | Go down |
| Neumel, Lowmel, Heritage Utility | UGGplush wool blend | True to size, less stretch | Go up, especially with thick socks |
| Weather Hybrid styles | Sheepskin or UGGplush, waterproof build | True to size, firmer upper | Go up |
How sizes are listed on RunLife
Most UGG styles here are women's and listed in US women's sizes 5 to 10 with the EU size in brackets: US 5 (EU 36), US 6 (EU 37), US 7 (EU 38), US 8 (EU 39), US 9 (EU 40), US 10 (EU 41). The men's styles (Neumel Weather Hybrid, Neumel High, Heritage Utility, Venture Daze, Tasman Weather Hybrid) are listed in US men's sizes 7 to 12 (EU 40 to 45). Kids' styles use US kids' sizes 13K to 6K (EU 31 to 37).
Converting between them: a US men's size is roughly a US women's size minus 1.5 (men's 8 is close to women's 9.5), and a kids' size is roughly a women's size minus 2 (kids' 5K is close to women's 7, kids' 6K to women's 8). Measuring your foot and using the EU number is the most reliable route; our size guide explains how to measure at home in two minutes.
Kids' sizes: the cheaper route for small feet
The Classic Mini II (Kids) and Tasman Weather Hybrid (Kids) go up to 6K, which fits roughly a women's 8. Same suede, same sheepskin, a lower price. The only differences are a slightly narrower last and fewer colourways.
Wide or narrow feet
UGGs are medium width. Wide feet are usually fine because the sheepskin compresses sideways too; very wide feet should pick the Classic boots over the Tasman, whose braided collar is firmer. Narrow feet should size down without hesitation; a loose UGG slips at the heel and wears out the lining faster.
Frequently asked questions
Should I order UGGs a size bigger for socks?
No for sheepskin-lined styles; they are made to be worn barefoot or with thin socks. Yes, half a size to a size up, for the Neumel and other UGGplush styles if you plan on thick socks.
My new UGGs feel tight. Did I get the wrong size?
If your toes are not pressed against the end and the heel is not lifting, that is the normal day-one fit. Give them a week of wear at home.
Do UGGs stretch?
The lining compresses by about half a size. The suede upper stretches very little.
What if I get the wrong size?
Email contact@shoprunlife.com within 30 days with a photo of the size label and your foot length in cm, and we will sort out an exchange or a refund.
Delivery takes 10–15 business days. For Christmas, order by December 1.
Ready to choose? Start with Tasman vs Tazz or Classic Mini vs Ultra Mini, or browse the UGG collection.