On Shoe Size Guide

On fits true to size for most buyers: 72% of wearers report a true fit, 12% find it small and 16% find it large. Use the table below to convert your foot length in millimetres straight to US, UK, EU and CM sizes — the one measurement every system agrees on. Only standard (D) width is offered, so very wide feet may need to size up.

Best fit recommendation for On

For a 271 mm foot, On fits true to size. Best fit: US 10 (likely US 9–11), UK 9, EU 41, 27 cm — confidence 70%.

Recommended size for a 271 mm foot on On (best fit + range, not a guarantee)
Best fit Likely range UK EU CM Confidence
US 10 US 9–11 9 41 27 70%

Evidence: 2 sources · no lab measurement in this record

See how we calculate for the methodology. Sizes vary by model and foot shape; this is an estimate, not a guarantee.

Save your On size passport

Save your foot length and usual US size here, then reuse it on comparisons and other brand guides.

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On size conversion table

On sizes by foot length (240–300mm). US Men's, US Women's, UK, EU and CM.
Foot length US Men US Women UK EU CM
240mm 6.5 8 5.5 36 24
250mm 7.5 9 6.5 38 25
260mm 8.5 10 7.5 39 26
270mm 10 11.5 9 41 27
280mm 11 12.5 10 42 28
290mm 12.5 14 11.5 44 29
300mm 13.5 15 12.5 45 30

EU sizes are always rounded to a whole size — there is no exact half-size equivalent, so treat the EU column as the closest honest match.

Do On Running shoes run true to size?

On Cloud models generally fit true to size; the snug heel counter is intentional for running lockdown.

How On fits

Across our data On true to size. Of wearers, 12% report it runs small, 72% true to size, and 16% large.

On reported-fit distribution
Runs small True to size Runs large
12% 72% 16%

Where this data comes from

Built from 1 On record and 640 measurements. See how we calculate for how confidence is scored.

Model-specific fit verdicts — these run differently from the brand average, so check the exact silhouette you're buying.

How did On fit you?

Anonymous - no account needed, no email required. Your answer feeds our fit data and helps the next buyer get the right size.

This shoe felt: