Boonbuy Shoe Size Guide: Read the System Before the Number
A shoe size is useful only when you know which system and product it belongs to. Before choosing an option, identify the shoe, the size chart and whether the labels refer to men’s, women’s or children’s sizing.
Keep three questions separate: what your foot measures, what the shoe’s label says and how the specific model is intended to fit.
Identify the size system
Look for an explicit US, UK or EU label on the listing and its chart. A bare number such as “8” is not enough information.
| Information | What to record |
|---|---|
| Product | Model and selected option |
| Size label | System and men’s, women’s or children’s range |
| Length field | Whether it means foot length, insole length or a label |
| Width | Any width option or model-specific fit note |
Check the chart for the exact range you are viewing. Do not move a number from a men’s chart to a women’s chart, or assume the same number means the same fit across brands.
Measure your feet using the relevant instructions
Nike’s own footwear guide describes measuring both feet while standing and using the longer result with its chart. It also states that the CM label on its boxes and shoes is different from measured foot length. These are Nike’s instructions, not proof that every marketplace listing follows Nike’s sizing. Nike footwear measurements.
For your comparison notes, record each foot’s measurement and unit. Then check the intended product’s own guidance for how to use that measurement. Follow any model-specific width or fit instructions alongside the length information.
Keep foot length and insole length separate
Foot length measures your foot. Insole length measures a component inside a shoe. A printed CM or JP value is a size label whose meaning depends on the brand’s chart.
Consider a hypothetical listing that says only “27 cm.” Before using it, establish which of those three meanings applies. You cannot resolve that question by treating every centimeter figure as the length of the foot the shoe will fit.
Ask:
Does the 27 cm figure describe recommended foot length, a measured removable insole, or the printed size label? Which chart applies to this option?
Do not add or subtract a fixed allowance unless the relevant product guidance explains that method.
Use a familiar pair as a reference
Write down a pair you already find comfortable, including its model, labeled system and width if shown. A reference is most useful when you know what you like about its fit.
Then compare the new model’s chart and notes. A roomy toe box in one shoe does not establish the fit of another, and a familiar size label does not supply missing width information.
If two listings show the same style but different charts, keep their measurements separate and ask which chart describes the selected item.
Resolve gaps before choosing an option
Use the following checks when the information is incomplete:
- No size system: ask whether the options are US, UK, EU or another system.
- Only a centimeter value: ask whether it is foot length, insole length or a label.
- Between sizes: check the specific brand and model’s guidance.
- Width is important: ask about the width option or fit information instead of relying on length alone.
- Conflicting charts: confirm the chart that belongs to the selected product and seller.
There is no universal “always go half a size up” answer for all of these cases.
Check the order label in QC photos
Compare the warehouse item’s label with the option you selected. If the label cannot be read, request a clearer view. If a particular measurement would help, confirm whether it can be provided and how it will be taken.
A label photo can show a selected size. It cannot reproduce a fitting session or establish walking comfort. Read the QC photo guide before deciding what a picture actually answers.
Can a US-to-EU conversion table solve everything?
Use the relevant brand and product chart. A general table may help identify a system, but it does not settle model fit, width or unclear listing information.
Does an EU label mean the size is consistent everywhere?
Check the underlying chart and model details. The label alone does not establish how two different products fit.
Explore the Boonbuy shoes spreadsheet and open the complete listing to review the exact option.