Three centimetre values can describe three different things
A measured foot, a removable insole and a printed CM label can all produce centimetre numbers without describing the same object. Before comparing sizes, identify what each number measures and which model the chart belongs to.
Nike’s official footwear chart explicitly separates its CM/JP label from its foot-length measurement. That is a useful example of why a label should not be treated as a measured foot length across every listing.
Put the mismatched chart into a small record
Suppose your measured foot length is 26.4 cm. A hypothetical listing shows 27.0 cm beside insole length and an EU size beside another number. Record these as different fields. Do not subtract 26.4 from 27.0 and declare a fit result.
An insert can have a different shape and usable area from the space the foot occupies. You also need the selected model’s guidance and width context. The example explains a missing comparison; it intentionally does not recommend a size.
| Number in the example | What it measures | Still needed |
|---|---|---|
| 26.4 cm | The wearer’s measured foot | The chart’s measurement instructions |
| 27.0 cm | A stated insole measurement | Method and model-specific fit guidance |
| EU label | A size marking | The exact listing’s size mapping |
Ask one precise question before choosing a size
Ask whether the chart describes recommended foot length or a physical product dimension, and whether it applies to your selected model. If the seller provides a ruler photo, establish the endpoints rather than accepting the caption alone.
If the question remains unanswered, keep the candidate unresolved. A larger size is not a universal solution for a narrow toe box, a different shape or an unclear chart.
Add the use case for boots and winter shoes
Record the socks, fastening and opening you intend to use. These are additional questions beyond the printed size. Compare a reference pair that you can actually wear in a similar way, while keeping its label separate from the new listing’s chart.
A photograph can help compare visible shape or closures. It cannot tell you how the shoe feels during wear, establish grip on ice or prove weather protection.
Keep chart sources attached to the shortlist
Save the URL, selected model, chart type and unresolved question together. If you switch to another model or seller, repeat the check rather than carrying over a size answer that belonged to the earlier listing.
This makes a fit discussion from a buyer post more useful: you can see whether the model and chart match your candidate before borrowing the author’s conclusion.
Use the step-by-step checklist
Measure both feet, identify the chart type and resolve model-specific fit questions.
Check sneaker and boot sizing