Match sizes by foot length (cm), then check model fit — US labels alone can mislead across brands.
Chart match · verify brand charts(paid link)
Full converter (model + shoes you own) · Reverse: Thursday Boot Co. → On
Static conversion table (crawlable). Interactive tool above uses the same cm matching.
| On US | cm | Thursday Boot Co. US | Thursday Boot Co. EU |
|---|---|---|---|
| 6.0 | 23.4 | 6.0 | 38.5 |
| 6.5 | 23.9 | 6.5 | 39.0 |
| 7.0 | 24.4 | 7.0 | 40.0 |
| 7.5 | 24.9 | 7.5 | 40.5 |
| 8.0 | 25.3 | 7.5 | 40.5 |
| 8.5 | 25.8 | 8.5 | 42.0 |
| 9.0 | 26.1 | 8.5 | 42.0 |
| 9.5 | 26.6 | 9.5 | 43.0 |
| 10.0 | 27.0 | 9.5 | 43.0 |
| 10.5 | 27.4 | 10.0 | 44.0 |
| 11.0 | 27.8 | 10.5 | 44.5 |
| 11.5 | 28.3 | 11.5 | 45.5 |
| 12.0 | 28.7 | 11.5 | 45.5 |
| 13.0 | 29.6 | 13.0 | 47.5 |
On US 10 is 27.0 cm; Thursday Boot Co.’s nearest US is 9.5 (EU 43). On 10.5 (27.4 cm) maps to Thursday 10 (EU 44). Cloud 5 / Cloudmonster / Cloudsurfer are road shoes; Captain is a welted boot that this site already tells men to size down a half from sneakers — and this centimeter table is doing a similar half-drop from On’s scale.
Do not stack the Captain’s “men size down half from sneakers” on top of this chart’s 10 → 9.5. That would be a full size down from your On number. The wear-box is the conversion. If you already wear Captain a half down from Dunk, compare that resulting number to this table instead of subtracting twice.
Wide feet should use Thursday EE/EEE rather than reversing this half-down for width. Cloud 5’s own half-up (short/narrow On last) can cancel the chart drop if you convert from a sized-up Cloud instead of from a measured 27.0 cm. Convert from cm or from a TTS On model (Cloudmonster), then open the Captain guide for leather break-in.
Even when charts match, lasts differ. Check these guides:
On: Cloudmonster · Cloud 5 · Cloudsurfer
Thursday Boot Co.: Captain
Check prices: On Thursday Boot Co. (paid link)
Clothes sizing uses a separate compare path.