Allbirds Size Chart: US, UK, EU & CM for Women’s, Men’s and Unisex Sizes

Allbirds sizing has a quirk that catches many first-time buyers: new pairs come in whole sizes only. If you are a 9.5, there is no 9.5 to try, and Allbirds’ own advice on which way to go depends on the style. Wool Runners and Loungers say size up. Tree Runners say size down in one place and size up in another. This guide lays out the full women’s, men’s and unisex charts, shows exactly what Allbirds says about each family of shoes, flags where its own pages disagree, and gives a plain way to decide before you click buy.

Whole Sizes Only: What That Means for Your Order

On Allbirds’ help center, the answer to “Do you offer half sizes?” is short: “Allbirds come in whole sizes only.” The size chart still prints half sizes, which is confusing, so treat the half-size columns as reference points for conversion and not as sizes you can buy in every new style. Check each product page for the sizes offered. For example, the women’s Tree Runner Go page lists women’s 5 to 11 in half sizes, so offerings can vary by style.

For the rest of us, whole sizes create a real decision. If you wear a 9.5, both a 9 and a 10 are a half size away. Allbirds gives different guidance by family, so the right answer depends on what you are buying. The table in the style section below pulls every official statement together in one place.

Three things to keep in mind as you read:

• The soft, knit-style uppers on most Allbirds shoes flex with your foot, which is why Allbirds can sell whole sizes. That does not make a half size irrelevant. It just means the shoe forgives a small mismatch more than a stiff leather boot does.
• Fit notes change by style and sometimes by page, so the product page for the pair you want is the final word.
• A foot that looks wide or high-volume usually points to going up, not down.

Allbirds Women’s Size Chart (US, UK, EU, CM)

Allbirds’ women’s chart runs from US 5 to US 11. The UK column lists two values for whole sizes (for example 2 to 2.5 for US 5), which is how Allbirds prints it. For the general women’s scale, see our women’s shoe size chart.

Source: Allbirds women’s size chart. The CM column is labeled CM by Allbirds.

Allbirds Men’s Size Chart (US, UK, EU, CM)

Allbirds’ men’s chart runs from US 8 to US 14.5. One oddity: it jumps from 13.5 to 14.5 and does not list a 14, so we show it exactly as published. For the general men’s scale, see our men’s shoe size chart.

Source: Allbirds men’s size chart. The CM column is labeled CM by Allbirds.

Should You Size Up or Down? What Allbirds Says, Style by Style

This is the part most size guides skip. Allbirds publishes fit guidance in two places, the help center and individual product pages, and they do not always agree. Here is everything we found, with the source named.

Sources: Allbirds help center article on half sizes, Men’s Wool Runner product page, Women’s Tree Runner Go product page and Men’s Tree Runner product page.

The Tree Runner disagreement. The help center says most half-sized customers size down in the Tree Runner. The men’s Tree Runner product page says it “tends to run small” and recommends sizing up from your usual size. Both are Allbirds statements. We cannot say which is newer, so we do not pick a winner. What we suggest: if you are a clear whole size (say a true 10), order that size. If you are a half size or you like a snug barefoot fit, check the page for that exact style, and buy from somewhere with free returns so you can swap.

The Wool Runner is more straightforward. Both the help center and the product page lean toward sizing up if you are between sizes or have a wider foot.

Worked Examples for Half-Size Wearers

Using only Allbirds’ own guidance, here is how it plays out.

• You wear a men’s 9.5 and want Wool Runners. Allbirds says to size up in the Wool collection, so order a 10.
• You wear a women’s 7.5 and want Wool Loungers. Same rule: size up to an 8.
• You wear a women’s 8.5 and want Tree Skippers or Tree Toppers. Allbirds says most half-sized customers size up in those, so look at a 9.
• You wear a men’s 10.5 and want Tree Runners. The help center says most half-sizers size down, the product page says to size up. This is where you should check the current page and keep your return window open.
• You wear a whole size and have a wide foot. Allbirds says to go up to the next full size in each silhouette.

None of this replaces trying the shoe on. It just means you can start from the right guess.

Wide Feet: Is There an Allbirds Wide Width?

Many shoppers search for an Allbirds wide width. The pages we checked list width only as average and do not mention separate wide-width options, and they do not describe any style as wide or narrow. The company’s own advice for a wider foot is simple: go up to the next full size in each silhouette. If you are unsure about your width, our shoe width guide explains how to tell. Knit-style uppers give a little, but a foot that is too wide for a size will still feel pinched at the sides, so do not rely on stretch.

Allbirds Unisex Sizing and Why to Use One Chart at a Time

Allbirds also publishes a unisex chart that pairs US women’s and US men’s sizes with EU, UK and CM. We show it in full below.

* Allbirds prints this value as 39, which breaks the sequence between 28 and 30, so we show 29 and flag it. We also left out the Chinese size column.

A caution: do not convert between men’s and women’s using the EU numbers alone. On Allbirds’ own charts, EU 41 is women’s US 11 and men’s US 8, three US sizes apart, and the CM column does not match either. Use the chart for your own gender, or the unisex chart if the shoe is sold that way. For a general men’s to women’s rule, see our men’s to women’s conversion chart.

Measuring Your Foot Before You Order

Allbirds’ size chart shows a CM column but the page we read does not explain how it was measured, so we recommend comparing it with your own measurement as a rough guide only. Stand on a sheet of paper in the socks you usually wear, mark the longest toe and the back of the heel, measure the distance, and compare the larger foot with the chart. Our how to measure foot size at home guide has the step by step. If your measurement lands between two sizes, the Allbirds rules above for your style should decide.

Washing, Care and Keeping the Fit You Chose

Allbirds says many of its shoes are machine washable. The Men’s Wool Runner page says the shoe is “washing machine approved” and to remove the insoles and laces and wash the insoles by hand. The Tree Runner pages say to remove the insoles, hand wash them separately and let everything air dry. Following these steps matters for fit, because a pair that you dry in a way it was not meant for can feel different when you put it back on. For general care steps, see our shoe care guide.

What About Kids’ Allbirds?

The Allbirds size chart we read lists women’s, men’s and unisex sizes and no kids’ chart. If you are fitting a child, the smallest unisex sizes may overlap with large youth sizes, but we do not claim an official kids’ conversion. For kids’ fit, use our kids’ shoe size chart and youth shoe size chart.

A Five-Minute Fit Test When Your Pair Arrives

Because Allbirds are whole sizes only, a quick test at home is worth doing before you wear them outside. This is general fitting advice, not an Allbirds rule.

1. Wear the socks you will actually use. Thin socks and thick socks can change the fit by roughly half a size.
2. Stand up, do not sit. Your foot spreads when it carries weight, so judge the fit standing.
3. Check the toes. You should be able to wiggle them. If your longest toe presses the front, the pair is too small.
4. Check the heel. Walk across the room. A heel that lifts a little in a soft knit upper is normal at first, but a heel that slides is a sign the pair is too big.
5. Check the sides. Pinching across the widest part of your foot is the classic sign you needed the next size up, which matches Allbirds’ advice for wider feet.
6. Keep them clean and indoors for a day. Many retailers only accept returns of unworn or lightly tried-on pairs, so check the policy before you walk outside.

If you are torn between two sizes, buy the one that passes the toe and heel checks together, even if it is not the size you expected. The number on the box is less important than how the pair feels on your foot.

Allbirds Compared With Other Everyday and Running Shoes

Allbirds’ soft knit fit is different from structured running shoes. If you own On, HOKA, Saucony or New Balance, use their charts for those and your measured foot length for Allbirds, not a direct size swap.

Allbirds Sizing: Your Questions Answered

The Short Version Before You Buy

With Allbirds, the style matters as much as the size. Check whether you are buying a Wool or a Tree shoe, read the fit note on that product page, and use the ‘size up if in doubt’ rule for Wool shoes and wide feet. Keep your return window open for Tree Runners, where Allbirds’ own pages differ.

More Everyday and Running Shoe Size Guides

Sources

• Allbirds size chart
• Allbirds help center: half sizes
• Allbirds Men’s Wool Runners
• Allbirds Women’s Tree Runner Go
• Allbirds Men’s Tree Runners