Both are On models, but lasts differ. Cloud 5 is labeled Runs Small (Runs small and narrow — most size up half; wide feet especially). Cloudmonster is True to Size (True to size; half up if wide).
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.
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.
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.
| Cloud 5 | Cloudmonster | |
|---|---|---|
| Verdict | Runs Small | True to Size |
| Advice | Runs small and narrow — most size up half; wide feet especially | True to size; half up if wide |
| Width | Narrower/streamlined vs Cloudmonster; elastic speed-lace is snug | More forefoot room than Cloud 5 for many |
| Break-in | None | None |
| Fit offset | +0.5 | +0 |
| Confidence | medium | medium |
If the left model fits at the listed size, start here in the right model (chart + fit offsets).
| If Cloud 5 fits | Try Cloudmonster | Note |
|---|---|---|
| US 7 | US 6.5 | offset -0.5 |
| US 7.5 | US 7 | offset -0.5 |
| US 8 | US 7.5 | offset -0.5 |
| US 8.5 | US 8 | offset -0.5 |
| US 9 | US 8.5 | offset -0.5 |
| US 9.5 | US 9 | offset -0.5 |
| US 10 | US 9.5 | offset -0.5 |
| US 10.5 | US 10 | offset -0.5 |
| US 11 | US 10.5 | offset -0.5 |
| US 12 | US 11.5 | offset -0.5 |
Full Cloud 5 guide · Full Cloudmonster guide · Reverse compare · Open in converter