ON Running Size Guide —
True to Size?
Size converter for every ON model plus model-specific fit notes, upcoming collab drops, and buy links in your exact size.
| Model | Fit Verdict | Recommendation | Notes |
|---|---|---|---|
| Cloud 5 | True to Size | Your normal size | Most popular ON model — consistent, standard fit |
| Cloud 5 Waterproof | Go Half Down | ½ size down | Waterproof lining reduces internal volume slightly |
| Cloudmonster / Cloudmonster 2 | True to Size | Your normal size | Wide toe box — very roomy, true for most foot shapes |
| Cloudrunner / Cloudrunner 2 | True to Size | Your normal size | Consistent fit, standard width |
| Cloudnova | Go Half Down | ½ size down | Lifestyle silhouette runs slightly long — most buyers size down |
| Cloudnova Form | Go Half Down | ½ size down | Same last as Cloudnova — same advice |
| Cloudsurfer | True to Size | Your normal size | Race-day fit, snug but not narrow — true to size |
| Cloudsurfer Trail | Go Half Up | ½ size up | Trail upper is narrower — wider feet should size up |
| Cloudeclipse | True to Size | Your normal size | Max cushion trainer — roomy and consistent |
| The Roger (Federer collab) | Go Half Down | ½ size down | Tennis-inspired lifestyle shoe — runs long like Cloudnova |
| Cloudflyer / Cloudflyer 4 | True to Size | Your normal size | Wide version available — standard width is TTS |
| Lightspray (2026 drop) | True to Size | Your normal size | 3D-printed upper molds to foot — check ON directly for sizing at launch |
ON collab and limited releases — not performance restocks. Updated as announcements land.
Drop dates are estimates based on announcements and brand cadence — always verify on on.com before the release day. ON does not use SNKRS or StockX for primary drops; all limited releases go through on.com directly.
| US Men's | US Women's | UK | EU | CM |
|---|---|---|---|---|
| 6 | 7.5 | 5.5 | 38.5 | 24.0 cm |
| 6.5 | 8 | 6 | 39 | 24.5 cm |
| 7 | 8.5 | 6 | 40 | 25.0 cm |
| 7.5 | 9 | 6.5 | 40.5 | 25.5 cm |
| 8 | 9.5 | 7 | 41 | 26.0 cm |
| 8.5 | 10 | 7.5 | 42 | 26.5 cm |
| 9 | 10.5 | 8 | 42.5 | 27.0 cm |
| 9.5 | 11 | 8.5 | 43 | 27.5 cm |
| 10 | 11.5 | 9 | 44 | 28.0 cm |
| 10.5 | 12 | 9.5 | 44.5 | 28.5 cm |
| 11 | 12.5 | 10 | 45 | 29.0 cm |
| 11.5 | 13 | 10.5 | 45.5 | 29.5 cm |
| 12 | 13.5 | 11 | 46 | 30.0 cm |
| 13 | 14.5 | 12 | 47.5 | 31.0 cm |
Do ON Running shoes run true to size?
Most ON models run true to size — particularly the Cloud 5, Cloudmonster, Cloudrunner, and Cloudsurfer. The main exceptions are lifestyle models like the Cloudnova and The Roger, which run slightly long and are best sized down half a size. If you're buying your first pair of ON shoes, start with your normal US Men's or Women's size and check the model-specific guide above.
ON Running men's vs women's sizing
ON uses the standard 1.5-size offset between men's and women's sizing — the same as Nike and Adidas. A US Women's 9 = US Men's 7.5 in ON Running. Most ON performance models are available in dedicated men's and women's versions with gender-specific lasts, so you should always shop in your correct gender category rather than converting.
Are ON Running shoes available on StockX or GOAT?
Standard ON performance models are not typically found on StockX or GOAT — they're sold through ON's website and authorized retailers like Zappos and Running Warehouse. However, limited collab releases like The Roger and the Zendaya Cloudnova do appear on the resale market after selling out, and those can be found on GOAT. For the primary drop, always go to on.com directly.
ON Running vs Nike sizing — are they the same?
Generally yes — ON uses the same US Men's numbering system as Nike. A US 10 in Nike is a US 10 in ON for most models. The fit profile is different though: ON shoes tend to have a more precise, performance-oriented fit compared to lifestyle Nike models like the Air Force 1. If you're used to Nike Dunks and sizing up half, you may not need to do that in ON.