Both are On models, but lasts differ. Cloudmonster is labeled True to Size (True to size; half up if wide). Cloud 5 is Runs Small (Runs small and narrow — most size up half; wide feet especially).
Cloudmonster is one of On’s more forgiving lasts and usually fits true to size. Wide feet or long-run swelling may still prefer half up. Heel lockdown is generally secure at TTS.
Cloud 5 is frequently called shorter/narrower than Cloudmonster, and the elastic speed-lace system keeps a snug wrap. Half a size up is common for all-day comfort or wider feet; narrow feet wanting a sleek fit can try TTS first.
Use the table below as a starting point from fit offsets — then confirm with try-on or returns. Width can matter more than length between these two.
| Cloudmonster | Cloud 5 | |
|---|---|---|
| Verdict | True to Size | Runs Small |
| Advice | True to size; half up if wide | Runs small and narrow — most size up half; wide feet especially |
| Width | More forefoot room than Cloud 5 for many | Narrower/streamlined vs Cloudmonster; elastic speed-lace is snug |
| Break-in | None | None |
| Fit offset | +0 | +0.5 |
| Confidence | medium | medium |
If the left model fits at the listed size, start here in the right model (chart + fit offsets).
| If Cloudmonster fits | Try Cloud 5 | Note |
|---|---|---|
| US 7 | US 7.5 | offset +0.5 |
| US 7.5 | US 8 | offset +0.5 |
| US 8 | US 8.5 | offset +0.5 |
| US 8.5 | US 9 | offset +0.5 |
| US 9 | US 9.5 | offset +0.5 |
| US 9.5 | US 10 | offset +0.5 |
| US 10 | US 10.5 | offset +0.5 |
| US 10.5 | US 11 | offset +0.5 |
| US 11 | US 11.5 | offset +0.5 |
| US 12 | US 12.5 | offset +0.5 |
Full Cloudmonster guide · Full Cloud 5 guide · Reverse compare · Open in converter