Do On Running Shoes Run True to Size?
Complete Size Guide
On Running generally runs true to size — but the narrow toe box and model-specific variations mean getting your size right matters more than with most brands.
Yes — On Running shoes are generally true to size. Order your normal US size. The most important thing to know is that On Running has a narrower toe box than most brands. If you have wide feet, On Running is likely not the right choice — or you may need to size up half a size to get more room in the toe box.
On uses a European sizing scale internally, so there can be slight variations between models. If you're between sizes, go half a size up — On's toe box doesn't have a lot of wiggle room.
On Cloud 5
True to SizeOn's most popular everyday shoe. True to size. Narrow toe box — wide feet should size up 0.5 or choose a different brand.
On Cloudmonster
True to SizeOn's max cushion model. True to size and slightly wider than the Cloud 5. Best On option for wider feet.
On Cloudswift 3
True to SizeUrban runner / travel shoe. True to size. Sleek profile — not for wide feet.
On Cloudrunner 2
True to SizeStability road runner. True to size. Wider than Cloud 5 through the midfoot.
On Cloudsurfer
Runs Slightly SmallSome buyers report this runs half a size small. Consider sizing up 0.5 especially if you have a wider foot.
On Cloud X 3
Narrow FitTraining shoe with a snug, performance fit. True to size in length but narrower than lifestyle models. Wide feet: size up.
| US Men's | EU | UK | CM |
|---|---|---|---|
| 7 | 40 | 6 | 25 |
| 7.5 | 40.5 | 6.5 | 25.5 |
| 8 | 41 | 7 | 26 |
| 8.5 | 42 | 7.5 | 26.5 |
| 9 | 43 | 8 | 27 |
| 9.5 | 43.5 | 8.5 | 27.5 |
| 10 | 44 | 9 | 28 |
| 10.5 | 44.5 | 9.5 | 28.5 |
| 11 | 45 | 10 | 29 |
| 11.5 | 46 | 10.5 | 29.5 |
| 12 | 46.5 | 11 | 30 |
| 13 | 47.5 | 12 | 31 |
| US Women's | EU | UK | CM |
|---|---|---|---|
| 5 | 36 | 3 | 22 |
| 5.5 | 36.5 | 3.5 | 22.5 |
| 6 | 37 | 4 | 23 |
| 6.5 | 37.5 | 4.5 | 23.5 |
| 7 | 38 | 5 | 24 |
| 7.5 | 39 | 5.5 | 24.5 |
| 8 | 39.5 | 6 | 25 |
| 8.5 | 40 | 6.5 | 25.5 |
| 9 | 40.5 | 7 | 26 |
| 9.5 | 41 | 7.5 | 26.5 |
| 10 | 42 | 8 | 27 |
| 11 | 43 | 9 | 28 |
On vs Nike: On runs slightly narrower. Same size works in length but wide-footed Nike wearers may find On tight.
On vs Hoka: Hoka runs wider. If you wear Hoka 10 comfortably in standard width, On 10 may feel slightly snug through the toe box.
On vs New Balance: New Balance runs wider. On 10 = NB 10 in length, but NB is more accommodating for wide feet.
On vs Adidas: Very similar sizing. Order the same size.
On Running is not a wide-foot friendly brand. They do not offer official wide widths in most models. If you have wide feet, consider the Cloudmonster (their widest standard model) or look at Hoka, New Balance, or Brooks instead — all of which offer genuine wide width options.
If you love the On aesthetic but have wide feet, try sizing up half a size — this gives more room in the toe box at the cost of a slightly longer fit.
Not Sure Between Hoka and On?
See our full side-by-side comparison for walking, travel, and standing all day.
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