How running shoes should fit

Most running shoes that get abandoned weren't bad shoes — they were the wrong size, the wrong width, or bought for how they looked in the box rather than how a foot behaves at mile eight. Fit is boring, which is why it's the thing worth getting right first.

The short answer

Standing up, in the socks you run in, you want roughly a thumb's width of space between your longest toe and the end of the shoe. The heel should hold without slipping, the midfoot should feel wrapped but never squeezed, and your toes should be able to splay. If you're between sizes, go up.

Feet swell as you run and as the day goes on, so try shoes in the afternoon, not first thing. And fit for your bigger foot — almost everyone has one.

Length: why runners size up

That thumb's width isn't tradition for its own sake. On every stride your foot slides forward slightly and spreads under load; downhills push toes into the front of the shoe. A road shoe that's "your size" in the shop is often a half size short at the end of a long run, and that's where black toenails come from.

Most runners end up half a size to a full size above their everyday shoe size. There's no universal rule — brands last their shoes differently — but if your run shoes match your office shoes exactly, that's worth questioning.

UK, US and EU sizes don't agree

The same foot can be a UK 9, a US 9.5 or 10, and an EU 43 or 44 — and the conversion isn't even consistent between brands, because each maker rounds its size chart differently. Treat the printed conversions as a starting point, not a fact, and when you know your size in one brand, anchor on that brand's chart rather than a generic table.

This is also why we track stock per size on every offer rather than "in stock" at model level: a discount that exists in a UK 8 and not in your UK 10½ isn't a discount for you.

Width is the fit problem nobody checks

Length gets measured; width gets guessed. If you get numbness across the forefoot, hot spots under the ball of the foot, or your little toe rides the sidewall, the shoe is probably too narrow — going up a size makes it longer, not wider, and often makes things worse.

Several brands cut the same model in multiple widths: for men, D is standard and 2E/4E are wide and extra-wide; for women, B is standard and D is wide. Wide fits usually cost the same as the standard cut, but retailers stock far fewer of them, so they sell through unevenly — which is exactly the kind of gap a per-size price board is for.

Size 13 and up

Big sizes are where fit advice meets availability reality: fewer models are made above a UK 12, retailers order fewer pairs, and the pairs that exist sell out in ways the product page doesn't show. If that's you, the practical advice is unglamorous — when a shoe fits, buy it while your size exists, and check the actual size-level stock rather than the model-level "in stock" badge. Every board on this site shows availability for your size, not just the shoe.

When the fit changes under you

A new version number can mean a new last. "The v3 fit me" does not guarantee the v4 will, and brands rarely announce it. If a model update changes how a shoe fits you, the outgoing version is usually still on sale — often heavily, in the colourways nobody photographed for Instagram. See the colourway lottery for why that discount is bigger than you'd expect.

Wide-fit options on the board now

Wide cuts we're tracking live, cheapest colourway first — each links to its per-size board:

Cheapest live colourway per product — prices move, the board follows.