Figuring out or trying to convert your Australian shoe size to US isn’t always as easy as you’d think.
Different countries use different systems, and most of them were created long before anyone thought about standardizing anything. So yeah—sizes don’t always match up, and that can be a pain.
But don’t stress.
In this guide, I’ll break it all down for you in plain English. We’ll go over why the sizing differs, how Aussie sizes compare to US ones, and how to find your fit without second-guessing every number.
Plus, I’ll show you how real Aussie brands like Blundstone, RM Williams, and Western Boot Barn handle sizing—because theory is nice, but real-life examples are better.
And oh—if you’re also curious about how American sizes compare to European ones, I’ll walk you through the whole US-to-EU shoe sizing thing in a way that actually makes sense.
Let’s dive right into it…
Australian Shoe Size to US Size
If you’re just looking for a quick answer, don’t overthink it—check out the AU to US shoe size converter calculator I’ve added. It’ll give you your size in seconds and save you the back-and-forth.
AU to US Shoe Size Calculator
But if you’re like me and want to actually understand why the numbers don’t always match up, keep reading. There’s more to it than you’d think.
Now, most Aussie stores actually follow the US sizing system—at least on the surface.
So if you’re looking at women’s shoes in Australia, chances are the number on the box is the same as what you’d see in the US. An AU women’s 8 is a US women’s 8 too. Easy.
But here’s where it gets a little twisty—men’s sizes in Australia don’t follow the same pattern. Instead of using the US scale, men’s shoes in Australia usually follow the UK system.
That means they run about a size smaller than the US equivalent. So if you’re a guy who wears a US size 9, you’d probably be a size 8 in Australian men’s sizing.
Now, to make things even more interesting, some stores in Australia don’t even follow this strictly. You might walk into one shop and see men’s shoes labeled with UK sizes, then go to another store down the road and they’re using US sizes instead. No warning, no explanation.
So here’s what matters:
– If you’re shopping for women’s shoes in Australia, you’re good—AU = US.
– If you’re buying men’s shoes, remember this: AU = UK, which is one size down from US.
Simple, but also kind of not.
👟 Women’s Shoe Size Chart (AU = US)
| AU Size | US Size |
|---|---|
| 4 | 4 |
| 4.5 | 4.5 |
| 5 | 5 |
| 5.5 | 5.5 |
| 6 | 6 |
| 6.5 | 6.5 |
| 7 | 7 |
| 7.5 | 7.5 |
| 8 | 8 |
| 8.5 | 8.5 |
| 9 | 9 |
| 9.5 | 9.5 |
| 10 | 10 |
| 10.5 | 10.5 |
| 11 | 11 |
| 11.5 | 11.5 |
| 12 | 12 |
👞 Men’s Shoe Size Chart (AU = UK = US – 1)
| AU Size | AU Size |
|---|---|
| 5 | 4 |
| 5.5 | 4.5 |
| 6 | 5 |
| 6.5 | 5.5 |
| 7 | 6 |
| 7.5 | 6.5 |
| 8 | 7 |
| 8.5 | 7.5 |
| 9 | 8 |
| 9.5 | 8.5 |
| 10 | 9 |
| 10.5 | 9.5 |
| 11 | 10 |
| 11.5 | 10.5 |
| 12 | 11 |
| 12.5 | 11.5 |
| 13 | 12 |
| 13.5 | 12.5 |
| 14 | 13 |
| 14.5 | 13.5 |
| 15 | 14 |
So yeah, next time you’re shopping Aussie sizes, double-check the chart or ask the store staff what scale they’re using. Saves you from squeezing your feet into the wrong size.
Ever had to return shoes from a trip abroad just because of this mix-up? What would you do if your dream pair was only in “maybe your size”? Try it or walk away?
Related:
By the way, if you want to get a handle on how Canadian sizes compares to US sizes, take a look at my detailed Canadian to US shoe size guide.
Blundstone Sizing
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Blundstone throws a little curveball when it comes to sizing—and honestly, I kind of love it. You know how in most brands, a half size means just a tiny bit longer? Well, not here. At Blundstone, a half size doesn’t change the length of the boot at all. It only adds a little extra width.
Yep, you heard that right. A 7.5 is just as long as a 7, it just gives your toes a bit more breathing room. So if your foot’s a little on the wider side, or you like thicker socks, that half size might be your sweet spot.
Now, let’s talk about converting from US sizes to Aussie ones—because Blundstones follow Australian/UK sizing, and that’s where things can get messy if you’re not paying attention.
For women, here’s the basic rule:
🡺 Subtract 3 sizes from your US size.
So if you wear a US women’s 8, you’d need a Blundstone size 5. It sounds wild at first, but trust me—it works.
For men, it’s a bit easier:
🡺 Just go down one size from your US men’s size.
So a US 10 would usually be an AU/UK 9 in Blundstone’s world.
But here’s something I’ve seen a few folks miss: some people end up needing to size down even more. I’ve heard stories of women going 2.5 sizes down, and men dropping by 1.5 sizes. So yeah, it’s not an exact science.
That’s why it helps to try them on if you can—or at least know your foot length in centimeters. Blundstone’s got conversion charts (and on their boxes), so keep one handy. Saves you from the whole return mess later.
Oh, and don’t forget—if you’re between sizes or want a roomier feel, go for the half size. Remember, it’s about width, not length.
Oh, and if you’re curious about how other Australian boot brands handle sizing—Viberg, for example—have got their own quirks when it comes to fit, so make sure to check out my full breakdown on Viberg boot sizing.
Redback Sizing
Redback boots also use Australian/UK sizing, which runs about one full size down from US men’s sizing. So, if you normally wear a US 10, you’d likely need an AU/UK 9.
For women, going two full sizes down from your US size tends to work better than their sizing recommendation.
One thing that makes Redback different is how they handle half sizes: they don’t make the boot longer, just wider. So an AU 9.5 is the same length as a 9 but offers more room across the foot, similar to going from a D to an E width in US terms.
If your feet are wide or you plan on using orthotics, the half size can make a big difference.
If you want a full breakdown of how Redback boots fit, including width tips, break-in info, and comparisons to other brands, I’ve put together a complete Redback sizing guide you can check out.
RM Williams Sizing
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Here’s what you need to know: Again, Australian sizing follows the UK system. That means it’s usually one full size down from US men’s sizes.
So if you wear a US 9, you’re most likely a UK/AU 8 in RM Williams. Sounds simple, right? It mostly is—once you know the trick.
Now, this one-size-down rule applies across the board. Whether you’re considering their classic Craftsman boots, a sleek pair of Chelseas, or anything else from the lineup—same idea.
But here’s the catch: RM Williams boots run narrow. So if your feet aren’t on the slim side, you’ll want to look at their H width instead of the standard G.
What’s the difference? About a quarter of an inch (0.64 cm) of extra space in the footbed—enough to make a real difference without changing the actual size.
Now, here’s a little sizing example that might help it click. Say you’re a US 8D in most boots. You’d probably go with a UK 7.5G in RM Williams.
But if that feels tight—especially around the toes—you might want to jump to a UK 8G, which is about a US 9D. That gives you the same snug fit around the heel and midfoot, but a bit more breathing room up front.
And hey, that’s kind of the goal with Chelsea boots’ fit: snug around the heel and instep, but still a bit of wiggle room at the toes.
If you’re planning to buy a pair of RM Williams boots, I highly recommend checking out my full guide on how RM Williams sizing works. I go into much more detail about widths, fit tips, break-in, and much more. It’ll save you the hassle of guessing—and probably a return or two.
Western Boot Barn Sizing
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Let’s take a closer look at how this all plays out with real shoes—because it’s one thing to talk about charts and theory, but what happens when you’re actually trying to buy a pair?
Western Boot Barn is a great example. You might expect an Aussie brand to use, well…Australian sizing. But nope! Most of their footwear is made using American sizes, and some even follow European sizing. Yeah, talk about a mix.
But don’t worry—they actually give some pretty helpful advice. They say to start with your usual Aussie size (like what you’d wear in dress shoes), not your running shoes.
Apparently, joggers can throw things off—probably because of all the extra padding and variation in fit.
Here’s where it gets more specific:
- For women, US and Australian sizes are usually the same. Easy.
- For men, they say US sizes are about half a size bigger. So if you’re normally an AU men’s 8.5, you’d likely wear a US 9 at Western Boot Barn.
Now, about those random letters next to the size—ever seen stuff like “9EE” or “7.5W” and thought, “What is that?” It’s all about width.
For women:
- B and M = medium or a bit narrow
- C and W = wide
And since Aussies tend to have slightly wider feet than Americans (yep, fun fact), Western Boot Barn often leans toward stocking the wider C and W options. Smart move.
For men:
- D, M, E = standard or slightly narrow
- EE, EW, W = wide
- EEE = very wide (like, if your feet always feel squished, this might be your moment)
And here’s what I love—they mostly stock the wider fits for men, because let’s face it, no one wants boots that pinch.
Now, let’s talk about why shoe sizing actually varies from country to country…
Why does shoe sizing vary so much around the world?
Have youever wondered why a size 9 in the US does not match a size 9 in Australia, or the UK, or Europe? Like, shouldn’t a 9 just be a 9 everywhere?
You’d think so, right?
Well, here’s the thing. Countries started coming up with their own sizing systems long before anyone thought, “Hey, maybe we should all agree on one standard.”
Back in the day, every country was kind of doing its own thing. It’s a bit like how we still have inches in the US but centimeters just about everywhere else. Same deal with shoes. Everyone had their own idea of what a shoe size should be—and they stuck with it.
You won’t believe this, but all of that happened before the International Organization for Standardization even existed.
So by the time the world started thinking about “universal” standards, it was already too late. Shoe companies, factories, and even local shoppers were already used to their country’s system. Imagine trying to convince millions of people to switch—good luck with that.
And here’s another thing—some countries base shoe sizes on the length of the foot, some on the length of the shoe itself, and some just use random starting points and go from there.
So yeah, if you’ve ever looked at a shoe size chart and thought, “Why is this so confusing?”—you’re not alone. It’s messy, but there’s a reason behind the chaos.
How to Measure Your Feet
So, you’ve checked out the Australian shoe size to US size converter (nice move), but now you’re wondering—how do I even know my true size in the first place?
Because honestly, guessing doesn’t always work. One foot’s a little longer, your joggers lie, and sizes vary by brand. Here’s how to do it right.
Best Option: Get Measured in a Store
Getting your feet measured by a pro is the best way to go. If you can make it to a good shoe store, do it. They’ve got the tools, the know-how, and they’ve seen every foot shape under the sun.
You’ll stand on a Brannock device (we’ll talk about that in a sec), and in a couple of minutes, you’ll walk out with accurate measurements of your length, width, and arch.
Why is this better than going DIY at home?
Because they catch things you might miss. Like if one foot is slightly bigger (which is super common), or if your arch is low and affecting how your size actually fits. A trained fitter can help you figure out if you need a different width or even a different style to match your foot shape.
What’s a Brannock Device, Anyway?
You’ve definitely seen one before—it’s that metal thing with sliders and numbers all over it that you step onto at the shoe store.
The Brannock measures three things:
- Length (heel to toe)
- Arch length (heel to ball of the foot)
- Width (across the ball of your foot)
This combo gives you a more accurate size than just measuring length alone. And here’s a fun fact: a lot of people actually wear the wrong size because they only focus on the toe length. So if your shoes never feel quite right, this might be why.
Can’t Get to a Store? You Can Measure at Home
No worries. If you can’t visit a store, you can still get a solid measurement at home.
Here’s what you’ll need:
- A piece of paper (A4 works fine)
- A pencil or pen
- A ruler or tape measure
- Socks you’d normally wear with the shoes
Here’s how to do it:
- Place the paper on a flat, hard surface (like tile or wood).
- Stand on it with your heel lightly touching a wall.
- Trace the outline of your foot—be sure to keep the pencil upright, not angled.
- Measure the longest part (toe to heel) and the widest part (ball of your foot).
- Repeat with the other foot—yes, you need both!
Once you’ve got those numbers, compare them to a size chart (like the one in the calculator). And if one foot is bigger, always go with the larger one. You can tweak the fit with insoles or lacing tricks later.
A Few Things to Keep in Mind
Measure later in the day. Your feet swell as the day goes on, so measuring in the evening gives you a more realistic size.
Stand up while measuring. Your weight spreads your foot out, and you want to capture that for accuracy.
Wear the right socks. Planning to wear thick wool socks with your boots? Measure with them on.
Don’t trust your sneaker size. Joggers and sneakers tend to have extra room, so they often give you a false sense of fit. Always go by your actual measurements, not just what’s on your Nikes.
Where Shoe Sizes Come From
A Quick History of the Numbers on Your Box
It All Starts With a Barleycorn
Ever wondered why shoe sizes jump in thirds of an inch? Blame King Edward I. Back in the 13th century, he defined an inch as three barleycorns—yep, the grain—and decided that a single barleycorn (1/3 of an inch) would represent one full shoe size.
It stuck. So to this day, the UK sizing system still has three sizes in every inch.
At that time, shoes were just soft leather wraps with soles. No one cared much about exact sizing because shoes molded to your feet. But that wouldn’t last long.
@alexschmidty your shoe size is measured in barleycorns 👟 #history #shoes #britishempire #imperialism #imperialunits #shoesize #footwear #sneakers #barleycorns #barley #corn
♬ Can I Kick It? (Extended Boilerhouse Mix) – A Tribe Called Quest
The Rise of Mass-Produced Footwear
Shoemaking stayed a local craft until the 19th century, when four key inventions changed everything:
- Isaac Singer’s sewing machine made stitching uppers faster.
- Lyman Blake’s sole stitching machine revolutionized how soles were attached.
- Farley Gilman’s last-turning lathe allowed exact-sized wooden lasts to be mass-produced.
- Jan Matzeliger’s lasting machine pulled the uppers over the lasts quickly and accurately.
That last piece—the last—is what determines the shoe’s actual size and shape. Once shoemakers could make consistent lasts in bulk, they could finally offer standardized sizing.
The 1876 Berne Exhibition: Sizing Gets Serious
The invention of shoe machines led to one big problem: how do you measure feet the same way everywhere?
That question was tackled at the Berne General Exhibition of Foot Clothing in Switzerland in 1876. Two key figures, Robert Knöfel and F.F. Erhardt, helped shape the modern UK and Continental systems. There, the UK size 5 was officially defined as 10 inches in length. From there, sizes went up and down in thirds of an inch.
So:
- Size 6 = 10⅓ inches
- Size 12 = 12⅓ inches
- Size 2 = 8⅔ inches
- Child size 13 = 8⅓ inches
- Child size 1 = 4⅓ inches
That explains why a size 6 isn’t half the length of a size 12—it’s just two inches shorter.
Continental Sizes and Metric Logic
The Berne Exhibition also introduced the Paris Points system, now known as European or Continental sizing. It’s a metric-based system where:
- 2 cm = 3 sizes
- Sizes start at 0 and move up accordingly
- So a UK 6 becomes a Continental 39, and a UK 12 becomes a Continental 47.
Widths Come Into Play
By 1881, W.H. Alden added another layer of precision. He studied thousands of custom-made lasts and created width fittings for every shoe size:
- Narrowest: A (or 1)
- Widest: EE (or 6)
This made it easier to account for different foot shapes, not just lengths.
Meanwhile, in the US…
The US didn’t attend the Berne Exhibition and developed its own system. In the American scale:
- A women’s size 7 is 10 inches long
- A men’s size 5.5 is also 10 inches
So while American sizing is similar, it’s not identical to UK or Australian sizing—which explains a lot of the confusion when converting between systems.
Now, where does Australia sit in all this?
How Australian Sizing Fits In
Australian sizing is a bit of a hybrid:
- Australian men’s sizes follow the UK system. So, if you wear a UK men’s 9, you also wear an AU men’s 9.
- Australian women’s sizes follow the US system. So, if you wear a US women’s 8, that’s the same as an AU women’s 8.
So when someone says “Australian sizes,” you need to ask two things: are we talking about men’s or women’s sizing? And is the brand actually using true Australian sizing or just tagging US sizes?
Some Aussie brands use US sizing for everything, especially in women’s shoes. Others stick to the more traditional UK-based system for men. That’s why a conversion chart—or even better, a brand-specific fit guide—is so helpful.
In short:
- AU Men = UK Men
- AU Women = US Women
But double-check with the brand… because not everyone plays by the same rules.
In Short…
Shoe sizing came from trial, error, and a few smart inventions. Shoemakers built the system, and academics helped organize it. And while the numbers might feel arbitrary today, they’re all rooted in history—and a few centuries of problem-solving.
Final Thoughts
Australian shoe sizing doesn’t have to be a mystery. The biggest takeaway is simple: for men, your Australian size is usually one full size down from your US size. So if you’re a US 9, you’re likely an AU 8. For women, Australian sizing usually matches US sizing. That’s the quick fix—but as always, it pays to look closer.
Australian brands like RM Williams, Blundstone, and others use this system, but each has its own quirks. Some run narrow, some fit long, and some change depending on the last or width.
I hope this guide helped clear up some confusion. And if you’re still unsure, don’t miss the specific sizing guides I’ve written for RM Williams, Blundstone, and Viberg—they go way deeper into fit, lasts, widths, and conversions.
What do you think—should the world just pick one system and stick to it? Or would that be asking for trouble?