As shoe fans and apprentice shoe reviewers, runners often keep looking for a reliable running shoe size comparison between brands.
We’re very lucky to have two runners from our team who have actually tested tons of running shoes. They’re going to tell us how different brands size their running shoes perhaps to help you avoid that depressing return cycle especially when we’re ordering running shoes online more and more often.
Let’s give the floor to Eric and Gary…
Running Shoe Size Comparison Between Brands
After wearing and testing loads and loads of different makes and models of running shoes over the last years, I’ve always been intrigued by the variation in sizes between each of the manufacturers and the discrepancies within their sizing guides.
Some running shoes may seem to run a little long, some a little short, some very narrow, and some very wide.
A lot of us these days opt to buy running shoes online, which is quite a convenient option because they can arrive straight to your door.
Although buying online is tainted with risk a little bit and nobody wants to open up their fresh new running shoebox with those new gleaming dream machines to lace them up only for them to be the wrong size.
There’s nothing more disappointing than that. There probably are more disappointing things in life, but for us runners and shoe geeks, that really takes the biscuit.
One other problem that constantly perplexes me is the fact that pretty much all of us have got one foot slightly longer than the other.
There are never any options to like order a left in an 11 and a right shoe in a 11.5. You just don’t get that option and I wish we did.
I measured up both of my feet using a few different methods and all of them pretty much came to the same conclusion that my right foot’s slightly longer than my left.
This made a lot of sense to me actually when I thought about it. Quite often, I feel that my right foot doesn’t have quite as much room.
So, the right foot is approximately five millimeters longer than the other. That might not seem like an awful lot, but it does seem to make quite a difference in running shoes, at least for me.
My left foot’s 28.3 centimeters and my right foot is 28.8 centimeters. In inches, that’s 11.14 against 11.34.
If I look at my shoes over the years, I’ve got shoes in four different sizes, 12, 12.5, 13, and 13.5. I also used to think I was a 12 and then in recent years, I’ve suddenly found that I’d like to have a bit more room in the toe box. I’ve gone with this thing that I should have a thumb width in the toe box.
There’s all these different numbers on the shoe boxes and I’ll try to help understand what these numbers mean and see how the different brands interpret them.
What I found is that different brands interpret the sizing differently.
So, if you’re a size something in one brand, you may not actually be that size in another brand because of the way they do the sizing. That’s definitely noticeable for me that in some shoes I have to take a 13, but the equivalent shoe in say a New Balance maybe a 13.5.
Quickly, let me take you through some of the running shoes I have and see the sizes I have in them.
- Adidas Adizero Boston 9: I have the UK 12.5.
- Nike Next%: I have the UK 13 which has a centimeter size of 32 (12.5 inches)
- New Balance Fresh Foam 1080v10 and v11: I have the narrow in the US 14 which comes up at UK 13.5.
- Hoka: I seem to be able to get away with UK 12.5 and US 13.
- Asics Roadblast: I seem to be able to easily take a US 13 or UK 12, which has a centimeter size of 30.5 (12 inches), which is a lot less than the Nike one.
- Brooks Hyperion: I have the US 14 or UK 13 with a 32-centimeter size (12.5 inches).
I’ve got that Alpha Fly and hopefully, some of you will be able to grab this shoe soon.
I found Nike size 11 UK to be 28.8 centimeters (11.3 inches) (That’s on their size guide online, but when you look at any Nike shoebox, there’s a slightly different thing going on.
The Alpha Fly seems a little more generous again in terms of size. It’s just that little bit longer, but I had no problems the other week on that half marathon time trial in this shoe. It was just gold on foot. It’s a beautiful pillowy-like feeling but with a bit of spring.
Certainly, there’s a really forgiving fit in the toe box with this one and I’d certainly recommend it if you’re going to go for it. Hopefully, you’ve gone true to size and not gone up or anything like that.
I think true to size is probably going to be spot on with the Alpha Fly. And remember what Michael Barrymore said “you don’t want any hot spots”
On a Nike Infinity React, it actually says 30 (11.8) centimeters for a UK size 11. But if we’re taking that 28.8-centimeter (11.3”) measurement as gospel, that means that my right foot’s right at the very end of the UK size 11 category, the threshold.
I actually opted for a size 11.5 in the Nike Next% Hakone edition which I find to fit so much better in an 11.5 rather than the 11 that I have in the green version of the shoe.
I really did benefit from the extra length in the toe box on that shoe. It’s just way more comfortable in terms of my little toes as well. It’s just a few millimeters, but it actually made all the difference.
Thinking about it, the left shoe is about 9mm too long or at least there’s a load of extra room there in the toe box, which just was unnecessary.
What I do is wear a thicker sock, which really gets other runners’ attention.
I don’t know if it’s the fit of the shoe or something, but it just felt so much better with the 11.5.
Pegasus & Turbo
It seems less prevalent in the other models though like the Pegasus 36, the 37, the 38, but those were fine for me in a size 11. Even the Pegasus Turbo, the Pegasus Turbo 2 were all fine with me in a size 11.
I’d even say perhaps with the Pegasus Turbo 2 I could have sized down maybe half a size. There still would have been ample room in the toe box.
Looking at Nike’s website, they show you how to measure your feet correctly. My feet are 30.2 centimeters (11.8”) and according to the Nike chart, I fall between UK 12.5 and UK 13 (US 13.5 and US 14).
But I most comfortably feel comfortable in the UK 13 and that gives me just 0.3 of a centimeter (0.11”) over and above what they say.
Nike basically seems to refer to the length of the insoles. So, the insole in my Turbo 2 is more or less 32 centimeters (12.5”).
My thumb width is about two centimeters long. With my actual foot being 30.2 (11.8”) and the actual length of the shoe being 32 (12.5”), then 30.2 + 2 comes for pretty much 32 in it.
So, that suggests that that is the exact same right size for me giving myself a nice thumb width in the toe box.
In the past, I have had some Nike shoes in a UK 12 including the original 4% Vapor Fly. In fact, I used UK 12 in pretty much all my Nike shoes up until a few years ago and I often wondered why they always felt a bit tight.
I think it’s finally daunted me that I was only giving myself half a thumb width there of room and now with the thumb width, I feel just so much more comfortable in these shoes.
Onto Adidas now …
For a UK size 11, Adidas quotes something very different to Nike. They’ve got a 28.4-centimeter (11.18) length on a size 11.
So, it’s about a 4mm difference unless you take the other measurement that’s on the box.
I tend to opt for an 11.5 in Adidas shoes, which just gives me a little bit more room. The 11 is just way too tight.
In the Takumi Sen (Sponsored), for example, this is quite a tight race shoe. So anyway, I went up half a size and it’s spot on.
Certainly, they always seem a little more narrow whether it’s the lasts that they’re using to create the shoes, I don’t know.
Their 11.5 is quoted at a 28.8-centimeter length (11.3”), which is the same as Nike in a UK size 11.
In fact, the Adidas sizing guide quotes a UK 11.5 is the same equivalent as a US size 12. So, another nod that you might need to size up half a size if you’re going to go for an Adidas shoe.
Maybe that’s why so many people are against Adidas shoes. It does seem odd. You don’t seem to see too many people using them in the UK. Maybe the occasional UltraBoost here or there in the UK, but it’s mainly Asics.
I think with the UltraBoost 4 back in 2018, I went up a half size in that as well. I think that’s a reoccurring issue and I always go up about half a size in Adidas.
So, do be careful and make sure you measure up both feet too.
On the Adidas shoe size guide, they’ve got exactly the same way to measure your foot that Nike have although interestingly their results aren’t quite the same.
So, Adidas recommends a size 13 for my 30.2-centimeter (11.8”) heel-to-toe length and I might get a 13.5.
The big problem for me in Adidas is they don’t actually do a 13 or a 13.5 in a lot of their performance shoes like the Boston 9, the Adios 5, the SL 20, etc.
If I do the thumb test on my Boston 9 in the UK 12.5, I only get about half a thumb width there at the top.
They sort of fit, but they’re much tighter and I feel much more comfortable in the UK 13 in the Nike than these ones.
When I measured the insole of the Boston 9, UK 12.5 is 31 centimeters (12.2”). So, the Bostons are not ideal for me, but I do like them because they come up in narrow. It’s a bit of a trade-off.
If you’re choosing a shoe in Nike and Adidas and you say what is your true to size, it may not be actually the same for each brand.
So, check out their charts and make sure you got the right length for you.
Let’s give the floor to New Balance…
I think New Balance found the right equilibrium between common sizing issues in other running shoes.
So, on the New Balance website, it says UK size 11 is 29.5 centimeters (11.6”), but in my experience, I don’t believe that.
Fuel Cell TC
Again, on the box of the New Balance Fuel Cell TC, Adidas quotes this 11.5 as a 30-centimeter shoe (11.8”).
I just don’t know how all this works. I think I’m just going to go on centimeters in the future because it just seems a much better way of doing it.
This size 11.5 Fuel Cell TC is a perfect fit for me. In terms of both feet, actually, it just feels spot on.
There’s not too much room there and I don’t have any issues with slipping or anything like that.
Fuel Cell Rebel
I remember when I first got the Fuel Cell Rebel from New Balance, that shoe just was really snug in a size 11.
I really wished I could have gone up half a size, but alas, where I bought it, they didn’t have any and they didn’t know when they were going to get any.
So, I would suggest being a little bit careful with New Balance sizing because they do seem to run a little short.
Beacon & 1080
Oddly though with New Balance, with the Beacon (Sponsored)original, I went true to size and that was fine.
However, I did go half a size up in the New Balance 1080v10 and that was again spot on.
So, whether that’s changed recently, the Beacons are slightly older shoes of course, and the TC and the 1080v10 are quite new and recent shoes.
In short, I think you can say that New Balance shoes do run a little bit snug or run a little bit short.
For my 28.3 and 28.8-centimeter feet certainly, the 29.5 centimeters (11.6”) quoted on the sizing guide just doesn’t add up. It’s just not right.
I think it’s important to remember though that New Balance do offer several different width fittings.
When I did measure up my feet in terms of width, I come in absolutely smack bang on a regular.
1080 & RC Elite
The length of the insole in the UK 13.5 in New Balance 1080v10 seems to be actually 31.5 centimeters (12.4”), but on their website, it says 32 (12.59”).
I’ve also measured it in the RC Elite and it’s also a 31.5. It seems to be a standard thing. So, effectively, New Balance UK 13.5 is equivalent to like a Nike UK 12.5 or Adidas UK 13.
What about Asics …
Asics is different again. For me, all Asics shoes have been absolutely spot-on in terms of a UK size 11.
Asics quote the size 11 at 29.5 centimeters (11.6”) and the 11.5 at 30 centimeters (11.8”). So, you can see my confusion and yours because they’re just all different.
The Glide Ride, the Evo Ride, the Nova Blast have all been spot on for me in a UK size 11.
I’ve never had any heel slippage or anything in Asics because the uppers on the Asics models are going to hug your foot like a carebear.
On the Asics site, they’ve got a similar diagram of how to measure the length of your feet. What’s different about Asics is the centimeter sizes they quote on their chart seems to refer to the length of your feet and not the length of the insole.
Again, mine’s a 30.2 (11.8”), and that suggests that in an Asics, I can get away with the 12.
Sure enough in the Meta Racer and the Roadblast, I do have a 12 although I’ve got a 13 in a Nova Blast and find them quite roomy. That probably explains why that is.
Again, be careful with Asics because their sizing does appear at least for me to come up longer than other brands.
It looks like I can almost get away with the 12 in Asics whereas I have to go 13 in a Nike and would go 13.5 in Adidas.
The box of my RoadBlast in the UK 12 shows 30.5 centimeters (12”) as it is on their size chart.
What is interesting though is that although the centimeter size for Asics says 30.5 (12”) in the UK 12, if I take out the insole of the RoadBlast and measure it, it actually comes up 32 centimeters (12.5”). That’s exactly the same as my Nike Turbo 2.
When I put the insoles side by side, they appeared to be pretty much exactly the same. That is basically saying that an Asics 12 is equivalent to a Nike 13. It’s a whole size difference.
Off to Hoka…
Hoka One One
I find Hokas to be similar in terms of Asics sizing, but I do find a size 11 UK to be right up there at the threshold of that size.
Hoka Rincon & Carbon X
I mean it says 29.5 centimeters (11.6”), but I’m not entirely sure that’s right. The Rincon did feel quite narrow and there wasn’t a huge amount of room in the toe box.
The Carbon X was a different story as it felt quite roomy. I’m not really sure that going up half a size in the Rincon would have helped, but certainly not in the Carbon X.
The Hoka Rocket X is one of these great carbon fiber running shoes.
Hoka also tell you to measure your foot in a similar way to Nike, Adidas, and Asics.
Rincon & Carbon X
My 30.2 (11.8) comes between a UK 12.5 and a UK 13. I’ve gone for 12.5 in the Rincon and the Carbon X and I think they fit pretty well.
On the Rincon Original at UK 12.5, Hoka seems to come up quite large because I’ve got pretty much a full thumb width there.
Unfortunately, I can’t measure the insole of a Rincon because it’s glued in as is the Carbon X (Sponsored). So, the centimeter size may be slightly misleading in the Hoka especially if you’ve got a glued insole.
Again, it’s another example of how the sizing sort of differs.
Brooks don’t actually seem to give an actual centimeter of your actual foot size, but the sizing on their website does seem very similar to what Nike do.
The Brooks UK 13 for me seems to be about right. So, the Brooks 13 is actually a 32-centimeter length (12.5”). When I measured Brooks, that seems to be pretty much what they say.
I think Brooks and Nike sizing is notionally the same because I had to send back the Hyperion Elite 2 in a 12.
I just felt there was not enough room for me because I was barely getting that half a thumb width at the top.
Although their size chart seems to also give it up around my size, they don’t actually give a centimeter size, but I think you can extrapolate when it says on the box it’s the 32 (12.5”).
So, I think basically Nike and Saucony sizing is exactly the same at least in my size. So, I’m happy to have to take a 13 in both of them.
I never actually had an ON shoe so it might be a good test to see what size I would actually take based on their size chart.
Unfortunately, they don’t seem to give an actual sort of centimeter actual foot length measurement, but in the men’s sizes, they do give the Japan size which seems to be the centimeter length of the insole.
So, I’ve seen that working in a 31.5 (12.4”) or a 32 (12.5”) length and that is equivalent to their UK 13.5, it seems.
I think if I were to get an ON shoe, I’d probably take an initial stab at 13.5. Unfortunately, they don’t do a 13 so I kind of stuck between the two.
You do see a lot of running shoe stores actually recommending that you go up half a size if you’re buying a running shoe.
I’m not entirely sure that that is a thing. I’m not sure why or what advantage they would have to say that to you, but in my experience, you need to try a shoe and see how it feels.
I recommend you half size up only if the shoe is too tight for you. Your running shoes should be ‘snug’, not too tight and not too loose, neither.
You need your running shoes to give your feet enough room when your foot is splayed out a little bit maybe towards the latter part of the day when you’ve had a lot of your weight onto your foot.
I also think that that’s the ideal time to try your running shoes to get the right fit.
- 12.5 is probably the best bet for me in a Hoka,
- 13 may be the best bet for me in a Nike,
- 13.5 may be the best bet for me in an Adidas,
- 12 may be the best bet for me in an Asics,
- 13.5 is the right size for me in a New Balance.
Also, think have you got a thumb width at the top?
Do you actually like that? Some people like a bit less in a racing shoe for example.
Work out what size shoe you think it fits you the best.
Measure the insole and work out exactly how long that one is. Use that as a bit of a benchmark to compare with other shoes from other brands.
Another thing to remember of course is that generally in running shoes, you want a bit more room than you would do in your normal sort of day shoes because your feet will expand.
I think that’s largely the purpose of that thumb width at the top. You certainly don’t want a shoe that’s rubbing against the toe box before you start because that’s going to be very comfortable and then those dreaded black toes will come up.
So as you can see, it’s quite a bit of discrepancy between the different manufacturers and models. We haven’t covered all the brands today, but you got the point.
Of course, the length of the insole is not necessarily the full picture because it kind of depends on how it actually sits in the shoe, how much padding there may be on the heel, or how tight the toe box is.
A good example of that is the comparison of the Boston 6 and the Boston 9. These are both allegedly in the UK 12.5. When we measured the insoles, they were exactly the same. But the Boston 6 is noticeably shorter than the Boston 9.
So, at least knowing how long your feet are and what shoe is meant to fit you in a particular brand gives you a head start.
So, that’s it for this running shoe size comparison between brands. Please do comment below with some of your running shoe sizing quirks and let us know your experiences in the different makes and models.
Perhaps you’ve had some different experiences than our reviewers and have a better running shoe fit comparison? That’s absolutely fine. It’ll be lovely to see some of your comments down below.
Happy Running and stay safe.