UGG Sizing Conversion

UGG Sizing Guide: US to UK Conversion | OD's Designer Clothing
UGG boots at OD's Designer Clothing St Helens

UGG Sizing Guide: US to UK Conversion

Buy Snug | Sheepskin Stretches | Half Sizes: Round Down

By OD's Designer Clothing | Updated April 2026 | 5 min read

UGG uses US sizing — not UK or EU — which is the first source of confusion for most UK buyers. A women's UK 5 is a UGG US 7. A men's UK 8 is a UGG US 9. Use the conversion table in this guide to find your correct size rather than guessing.

The second key rule: buy snug. UGG Classic boots and slippers are lined with genuine sheepskin, which compresses over the first few wears and conforms to the shape of your foot. A boot that feels slightly firm when first tried on will soften and mould — giving you a personalised fit. A boot that is too large from the start will stay too large.

1 | How UGG Fits

UGG Australia was founded in 1978 and uses US sizing across its entire footwear range. The brand does not use EU sizing as primary. All sizes on UGG boxes, labels, and product pages are US sizes.

UGG Sizing Rules at a Glance

  • US sizing: All UGG sizes are US — use the conversion table
  • Buy snug: Sheepskin lining stretches and conforms over time
  • Half sizes: Round DOWN (US 7.5 → buy US 7)
  • Wide feet: Go your true size or half a size up
  • Slippers (Tasman/Tazz): True to size — different rule applies

When you first put on a new pair of UGG Classic boots, the footbed may feel firmer and the boot may feel slightly snug, particularly across the toe box and instep. This is normal and expected. The sheepskin wool fibres compress and take on the shape of your foot within the first few wears. This is why UGG consistently recommends buying snug rather than loose.

2 | Half Sizes: Round Down, Not Up

UGG does not make boots in half sizes across most of its range. If your true foot size is a half size, UGG's official recommendation is to round down to the nearest whole size.

Half Size Rule

If your foot measures a US 7.5, order US 7. The sheepskin will give the small amount of additional room needed as the boot breaks in. Ordering US 8 risks ending up with a boot that never fits snugly, even after break-in.

Exception: if you have wide feet or very high arches, rounding up (to US 8 in the example above) may be more appropriate. Wide-foot customers should consider this when applying the general rule.

3 | US / UK / EU Conversion Table

UGG labels its footwear in US sizes. The table below converts to UK and EU equivalents for women's and men's styles.

Women's Size Conversion

UGG US Size UK Size EU Size Foot Length (cm)
5 3 36 22.0
6 4 37 23.0
7 5 38 24.0
8 6 39 25.0
9 7 40 26.0
10 8 41 27.0
11 9 42 28.0
12 10 43 29.0

Men's Size Conversion

UGG US Size UK Size EU Size Foot Length (cm)
7 6 40 25.0
8 7 41 26.0
9 8 42 27.0
10 9 43 28.0
11 10 44 29.0
12 11 46 30.0
13 12 47 31.0

Quick Conversion

Women's: UK size = UGG US size minus 2 (e.g. US 8 = UK 6). Men's: UK size = UGG US size minus 1 (e.g. US 9 = UK 8).

4 | Classic Boots vs Slippers vs Fashion Boots

Classic Short & Classic Tall

UGG's flagship boot. Buy snug — size down for half sizes. Sheepskin lining compresses significantly over first 3–5 wears. If too loose from the start, they will remain loose.

Ultra Mini & Classic Mini

Shorter shaft version of the Classic. Same sizing rule applies — buy snug, round half sizes down. Slightly less sheepskin volume than the full Classic so break-in is somewhat faster.

Slippers (Scuff, Coquette)

Open-backed slippers follow a true-to-size rule rather than the snug rule. The open heel means no containment, so sizing down would result in the slipper being too small. Order your standard size.

Fashion & Lace-Up Boots

Fashion boots (Neumel, Classic Braid) fit true to size. These have less sheepskin volume than the Classic and do not break in the same way. Order your standard converted size.

5 | Tasman & Tazz: Specific Notes

The UGG Tasman and Tazz are two of the brand's most popular styles and have a different fit profile from the Classic boot range. Both are mule-style (backless) slippers with a suede upper and sheepskin lining.

Tasman & Tazz Sizing

  • True to size — do not buy snug as with Classic boots
  • The backless silhouette means the foot needs to fill the shoe correctly from the front
  • If between sizes, go up rather than down (opposite to Classic boot rule)
  • Wide feet: go half a size up for comfort
  • The Tazz has a slightly chunkier sole than the Tasman but identical upper sizing

The Tasman and Tazz are designed for both indoor and outdoor wear. The suede upper does not stretch or soften in the same way as the Classic boot shaft — so the length you order is the length you get. Do not apply the Classic boot snug-buy rule to these styles.

6 | Measuring Your Foot

Step-by-Step Measurement

  • 1. Stand on A4 paper on a hard floor
  • 2. Trace around your foot — pencil held vertically
  • 3. Measure heel to tip of longest toe in millimetres
  • 4. Repeat for both feet, use the longer measurement
  • 5. Match to the foot length column in the table — this gives your EU size
  • 6. Convert EU to UGG US size using the table above
  • 7. If your measurement falls between sizes: round down for Classic boots, round up for Tasman/Tazz and slippers

Measure in the afternoon. For boots specifically, wear the socks you intend to wear — a thick wool sock versus a thin cotton sock can make the difference between a comfortable fit and one that feels too snug. UGG boots are typically worn with thin socks or no socks at all, so measure accordingly.


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