Why are shoe size numbers consistent but the actual shoe size varies per brand?


Shoe brands typically use the same number scale, but when you compare the actual size of shoes, the sizes are all over the place. Wouldn’t it make more sense to all agree on a set measurable size to make it easier on the customer to make a purchase?

Example: in US sizing, a 10.5 in one brand is the same as a 10 or an 11 in another brand.

In: 32

Sure. Whose brand gets to keep their standard as the universal one and which brands have to agree to change theirs to match their competitor’s standard?

Shoe sizes are measured in barlicorns. But it is not actually the shoe being measured but the last used to make the shoe. And while the last is shaped a bit like a foot it is usually much narrower and thinner. So the shoe size does not account much for the taper of the shoe. Different brands use different lasts and have different shapes to their shoes so the numbers turns out differently. Notice also that the US and UK use different numbers, even though both are in barlicorns.

Sorry to shatter your illusions, but shoe sizes are not necessarily the same inside a brand either. They can vary based on which factory and similar things, but even that does not mean so much…

My worst case was one morning not too many years ago (back when Adidas NMD was the hottest thing), I had queued in-front of a store. I bought two identical shoes in different colourways. The first fit like a glove, and I told the clerk I’d take the other without needing to try it on. He told me I ought to, and he was right. It deviated by a full size…

The real pro tip here is, check the Japanese sizing. That’s the cm length of the shoe. Then the only thing that can make a variance is the model, and the clerks will usually be able to help you with that. Some run slim, some are low, some are wide, etc. Who knows what you are!

People’s feet come in all different shapes. Some people have long skinny feet, some people have wide feet that spread out, some people have chunky feet shaped like bricks. Different shaped shoes are going to fit each shape of foot very differently. Each shoe company is defining what they consider is a “normal” foot, then scaling from there. The increments are the same between brands, but *you* with your unique feet, will find the fit different.

I thought I was 8.5 wide for a long time. Never felt quite ok with the size.

Tried Asics 10 regular size, damn it is so comfortable. So, I was undersizing by a full 1.5.

My adidas from Costco at size 10 fits like shit.
Nike downshifters are good but even 9.5 feel bad, I gotta try a size 10 Nike soon.