UGG® sizing: how to choose the right size

How UGG sizing works

UGG sizes its footwear by department, with separate scales for women, men and kids. On the US site the sizes are US sizes, and UGG's size chart lists each size with a heel-to-toe foot length and its UK, EU and other international equivalents.

Three things vary from style to style, so always check the product page before you order:

• Whole or half sizes. UGG notes that some of its styles are made in whole sizes only, while others are also offered in half sizes. The Classic boots are a whole-size line; the women's Classic Ultra Mini and Classic Tall II, for example, are listed in whole sizes only.
• Width. Product listings state a width, and the Classic boots are listed as a regular width.
• Size range. Some men's styles go up to size 18, which UGG groups as large sizes on its site.

Should you size down in UGG sheepskin boots?

For fully lined sheepskin boots, usually yes. UGG's help center says its women's Classic Collection tends to run large and recommends sizing down; if you are between sizes, choose the next whole size down, so a 7.5 becomes a 7. For men, UGG says its styles generally fit true to size, and men who fall between sizes in the Classic Collection should also go down to the next whole size.

The reason is the lining. A sheepskin boot is lined with dense wool fleece, and that pile compresses and molds to your foot as you wear it. UGG's own product pages for its kids' sheepskin boots note that the fit can feel a bit tight at first and that the sheepskin loosens with wear, and adult pairs behave the same way. A boot that feels comfortably snug on day one usually settles into a good fit, while one that feels roomy on day one can end up loose, with your heel lifting as you walk.

UGG's sizing guide adds a nuance about volume: if a style feels loose over the instep or across the middle of the foot, a smaller size can give a more secure fit.

If you are a half size

Because the Classic boots come in whole sizes only, half-size wearers have to choose, and UGG's advice for that collection is to go down to the next whole size. In styles that are offered in half sizes, start with your usual size.

A few practical tips (general good practice):

• If your foot is wide or high-volume, read reviews from owners with a similar foot before sizing down.
• If the retailer's return policy allows it, try both sizes indoors on a clean floor and send back the pair that fits less well.
• Try boots on at the end of the day and with the socks, or bare feet, you plan to wear them with.

How fit differs by style

Classic boots

The full sheepskin lining is what makes sizing down sensible. Expect a snug, even fit around the whole foot at first, without your toes pressing against the front. Shaft height changes how the boot sits on your leg, not the foot size you need; our Classic boots guide compares the heights.

Tall boots

For tall styles, the shaft matters as much as the foot. The product listings we checked give a shaft height but not a calf circumference, so if your calves are slim or athletic, look for reviews from owners with a similar build.

Platforms

A platform sole adds height and weight underfoot rather than length. Check the fit note on the product page, and see our platforms guide for how the thicker soles wear.

Slippers and slides

Slippers with sheepskin footbeds and linings pack down just like boots. Open-back slippers and slides are more forgiving on length because your heel is not enclosed, while closed slippers should feel snug without crowding your toes. Our slipper guide covers the main styles.

Shoes, sneakers and weather boots

Styles without a thick sheepskin lining have less to compress, so the size-down logic does not automatically apply; start with your usual size and the product page's fit note. For waterproof winter boots, try them with the socks you will actually wear in the cold. See shoes and sneakers and weather boots.

Men's and women's sizes

Men's and women's sizes are separate scales, so the same number does not mean the same foot length. Across US footwear generally, a women's size is about one and a half to two sizes higher than the men's size for the same foot, so a men's 7 is roughly a women's 8.5 or 9. Conversions vary between brands, so the reliable method is to compare heel-to-toe lengths on UGG's chart for each department rather than adding a fixed number.

This matters because several styles, including the Classic Short, Classic Ultra Mini and Tasman, are sold in both men's and women's versions, and people often shop across departments for a color or a size range. Men's sizes also go higher, up to 18 in some styles. Our men's guide covers the men's lineup.

US, UK and EU sizes

UGG publishes its own conversion chart, linked above and in the sources, with US, UK and EU sizes alongside heel-to-toe foot lengths. We have deliberately not reproduced a conversion table here. Generic shoe-size charts often disagree with brand charts by a half or even a whole size, and copied versions of UGG's chart on other sites do not always match each other or the current original.

• Use the chart on the UGG site for the country you are buying in, and match by foot length rather than by a size you know from another brand.
• UK sizes are offset from US sizes differently for men and women, so a conversion you know for one department will not work for the other.
• Buying secondhand or from abroad? Ask the seller which size system is printed on the label, and see our authenticity guide before you pay.

Kids' sizes

UGG splits its kids' range into babies, toddlers and big kids, and popular styles often appear in more than one group: the Bailey Bow II, for example, is sold in toddler and big-kid sizes, with a separate baby version. Toddler sizes carry a T after the number, as in 9T, while big-kid styles are sold in US kids' sizes such as 13 and then 1, 2, 3 and up.

Growing feet make kids' sizing a moving target. Some practical rules (general good practice):

• Measure both feet before every purchase and size from the longer one; children's feet can change size quickly.
• Compare the measured length with UGG's kids' chart instead of going by age, which is only a rough guide.
• Avoid buying far too big to grow into. A sheepskin boot that is loose from the start gets looser as the lining packs down, and a loose boot slips at the heel. A little room at the toe is fine; a lot is not.
• A snug first try-on is expected, since UGG says its kids' sheepskin boots can feel tight at first and loosen with wear. Toes pressed against the end are not.
• Some adults with small feet wear big-kid sizes. If you try this, compare foot lengths on the kids' and women's charts rather than converting by number.

Our kids' guide covers the styles and how they hold up.

How to measure your foot

1. Measure later in the day, when feet tend to be slightly larger, and wear the socks you plan to wear with the boots, or go barefoot if that is how you will wear them.
2. Stand on a sheet of paper on a hard floor with your heel against a wall and your full weight on the foot.
3. Mark the tip of your longest toe, which is not always the big toe. It is easier if someone else holds the pen.
4. Measure from the wall edge of the paper to the mark in inches or centimeters. Repeat for the other foot and use the longer measurement.
5. Find that heel-to-toe length on UGG's size chart for the department you are shopping: women's, men's or kids'.
6. For width, UGG's men's size guide explains how to measure across the widest part of the foot, and product pages state each style's width.

Break-in: what to expect

A new pair of sheepskin boots feels at its snuggest the first time you put it on. As you wear it, the fleece compresses and molds to your foot, which is why UGG says sheepskin loosens with wear. What changes, and what does not:

• Volume changes. The lining packs down, so a boot that hugs your foot will relax.
• Length barely changes. If your toes press against the front, the lining will not create room there; you need the next size up.
• Heel lift tells you a lot. A little movement at the heel is common in pull-on boots. A lot means the boot is too big, and it will get worse as the lining settles.

Wear new pairs indoors on clean floors for an evening or two before taking them outside. That way you can still return them if the size is wrong, subject to the retailer's policy.

Socks or no socks?

It is a personal choice. Sheepskin-lined boots and slippers are commonly worn barefoot, and many owners like the feel of the fleece against the skin; others prefer thin socks. Either works, but be consistent when you size (general good practice):

• Try on and size the boots the way you will usually wear them.
• Thick wool socks take up noticeable room in a fully lined boot. If you plan to wear them, factor that in before sizing down.
• Thin socks can help keep the lining fresher between cleanings; our care guide covers deodorizing and cleaning the inside.

Check fit with owner reviews

The quickest way to settle a sizing question is to ask people who already bought the style. Our review form asks every owner to rate the fit as runs small, true to size or runs large, so you can see how a particular model tends to fit. Browse all owner reviews, or go straight to popular styles:

• Classic Short · Classic Mini · Classic Ultra Mini · Classic Tall
• Tasman · Tazz · Neumel · Butte
• Men's Classic Short · Men's Classic Ultra Mini · Men's Tasman

When you write your own review, mention your usual size in a brand you wear often and whether you sized down. That one detail makes your fit rating far more useful to the next buyer.