UK, EU or US shoe size? Read the markings before comparing a pair

A shoe listing that says only “size 6” leaves a useful question unanswered: which sizing system? Start with the numbers actually printed inside each shoe, then look at the brand's own guidance for that range.

Clarks' official size guide separates UK sizes, its own EU equivalents, standard EU sizes and foot lengths. It also lists width fittings separately. This is a useful reminder to use a relevant brand chart rather than treating one conversion as universal.

Build a clearer size description

1. Photograph the markings in both shoes, including any width letter and model code.
2. Copy the printed system and number accurately. If the system is unclear, say so and show the label.
3. Link to the maker's guide for the appropriate adult or children's range when you can identify it.
4. State any replacement insole, alteration or other change you know about.
5. Describe your own fit experience as an observation, including relevant context, rather than a promise to the next wearer.

For buyers, compare the exact model and width with a pair you already wear comfortably. A size used by a different brand is a starting clue. An outside sole measurement includes material beyond the space available to the foot, so it is not a direct substitute for the maker's fitting method.

If a marking is worn away, ask for another angle or a close-up instead of guessing from appearance. Give yourself room to decide that a promising pair does not provide enough information.

Community prompt: What size information would make secondhand shoe listings easier for you to compare?

Vrool editorial guide. Prepared with AI assistance and checked against current feature information or the linked sources on 23 October 2026. Share your experience or suggest a correction below.