Your result
Click Calculate
Enter your values, then click Calculate result.How this calculator helps
This foot size calculator is an explicit chart comparison rather than a universal shoe-fitting formula. It uses Nike’s adult footwear chart checked on 6 October 2026, with the brand scope acknowledged before calculation. US men’s and women’s labels, UK, EU and CM/JP values are kept on the same source rows. Measured foot length is another input mode, with the published inch values converted to centimetres transparently.
How to use it
- 1
Confirm that the intended product uses the checked Nike adult chart.
- 2
Choose the input label scale or measured foot-length unit.
- 3
Enter the published size or compatible measured length and click Calculate result.
- 4
Review every matching row and current product fit guidance before using a label.
Formula and methodology
Use the published chart column as a lookup key; return all matching rows. For measured foot length between chart points, choose the next larger point. Foot cm here = published foot inches × 2.54.
The calculator applies the displayed arithmetic to the values entered on this device. It does not silently load a local tax rate, currency conversion or commercial assumption.
Worked calculation example
In the checked Nike adult chart, US men 9 corresponds to US women 10.5, UK 8 and EU 42.5. Its CM/JP label is 27, while the listed foot length is 10 5/16 inches, converted here to 26.19375 cm. The two centimetre-looking quantities are different. UK 6 occurs in more than one source row, so a UK 6 lookup returns all those rows instead of pretending the label identifies a single unique size.
How to interpret your result
Read the returned row as a set of source-chart labels and a foot-length reference. If several rows match, the output exposes ambiguity that another system’s single answer might hide. The converted centimetres describe the source’s rounded inch measurement. They should not be used to claim extra measuring precision, and neither those centimetres nor the CM/JP label independently guarantee a suitable shoe.
For different inputs or formulas, use Length Conversion Calculator; Clothing Size Chart Matcher; Ratio Calculator.
Related questions this calculator covers
- foot size calculator
- women's to men's shoe size conversion calculator
- shoe size converter and calculator
- adult shoe size converter
Scenario comparison
| Scenario | What it shows |
|---|---|
| US men 9 | the source row includes US women 10.5 and EU 42.5. |
| Repeated UK label | UK 6 returns every source match. |
| Foot length between points | the next larger checked point is selected. |
Common mistakes to avoid
- Using a brand-specific lookup as a universal fit guarantee.
- Confusing CM/JP box labels with measured foot centimetres.
- Discarding a second row when the input label is ambiguous.
Open the source chart and compare the US men 9 row across all five label columns. Convert 10 5/16 inches by multiplying 10.3125 by 2.54 to check 26.19375 cm. Look up UK 6 and verify the repeated matches. Test a length just below and just above one chart point, then confirm outside-range inputs are rejected rather than extrapolated.
Authoritative reference. Reviewed on 6 October 2026 for the specific disclosed method or measurement context. The arithmetic is independently implemented. A linked reference does not certify an individual result or extend the worksheet beyond its stated scope.What can affect the result?
Choose the label system before the value
A numeric shoe size has no unique meaning without its scale and chart. Select US men, US women, UK, EU, CM/JP box label or measured foot length before entering the number. A US women’s nine and a US men’s nine select different rows in this source chart. The worksheet does not guess a scale from the magnitude, country of residence or a previous purchase. Confirm that the intended item uses the stated adult chart.
Chart scope is brand specific
Shoe labels can differ between brands, product families and age groups. This page uses a specific Nike adult chart and does not claim that its row equals every brand’s corresponding label. Children’s and infant charts are not included, even where a similar-looking number appears. The scope confirmation starts unconfirmed so a casual number entry does not silently imply universal conversion. The worksheet is an independent comparison and is not affiliated with the manufacturer.
CM/JP label is not measured foot centimetres
The source distinguishes its CM/JP box label from measured foot length. They must not be substituted for each other just because both can look like centimetre values. This implementation retains the original box label and derives foot centimetres from the published inch row using the exact 2.54 conversion. That converted length retains the source inch rounding; it is not an independently measured or more precise manufacturer centimetre value.
Between-length lookup follows the stated rule
For a measured foot length between two listed points, the worksheet uses the next larger chart point, consistent with the source’s between-size instruction. Exact foot-length points return their matching row. Values outside the chart’s measurement span are rejected instead of extrapolated. Label modes require an exact published label and do not interpolate a made-up half size. A length comparison remains a chart starting point rather than proof of comfortable fit.
Duplicate labels are returned transparently
Some scale columns can repeat a label across distinct source rows. The UK and CM/JP columns include examples of this. When a label matches more than one row, the result lists every matching row and its other labels and length value. Choosing the first row arbitrarily would conceal a real ambiguity. Use the additional measurement or product information to understand which row applies rather than treating a duplicate lookup as an algorithm failure.
Length alone does not describe fit
Width, foot shape, socks, intended activity and the specific shoe construction can affect comfort and sizing choice. None of those is encoded in the chart lookup. The calculator cannot recommend a width, diagnose a foot condition or promise that a shoe will fit. Consult the actual product’s fitting notes and relevant return options before a purchase. When comparing two feet, preserve the measurement procedure and use the source’s current measuring guidance rather than a guessed length.
Check the current product chart
The bundled source snapshot makes this lookup reproducible, but manufacturers can revise charts or give product-specific instructions. The checked date is therefore part of the scope. Follow the official link and compare the intended product’s current guidance before relying on a label for a purchase. A row returned here establishes what is in the checked chart, not that a retailer has the size in stock or that a different shoe model uses identical sizing.
Privacy and browser processing
Values entered on this page are processed in the current browser session. SolvePilot does not require an account and does not receive the values entered into the calculator. Refreshing or closing the page clears the working values unless the browser itself restores a previous session. Avoid entering identifying or account information because the calculation needs summary values only.
Accuracy and verification
Accuracy depends first on input quality. Confirm definitions, scales, dates and source information before entering a value. Keep an independent record of any result used for planning because this page does not create an official statement or retain a calculation history.
Limits of this estimate
Using a brand-specific lookup as a universal fit guarantee. Read the returned row as a set of source-chart labels and a foot-length reference. If several rows match, the output exposes ambiguity that another system’s single answer might hide. The converted centimetres describe the source’s rounded inch measurement. They should not be used to claim extra measuring precision, and neither those centimetres nor the CM/JP label independently guarantee a suitable shoe. Entries remain on this device for the calculation and are not submitted to a calculation server. Browser floating-point arithmetic and displayed rounding do not establish real-world measurement certainty.
Sources and review information
Frequently asked questions
Is this a universal shoe-size conversion?＋
No. It uses a stated Nike adult chart.
Are CM/JP labels actual foot length?＋
No. The source distinguishes box labels from measured foot length.
What happens between measured lengths?＋
The next larger listed chart point is returned within the supported span.
Why can one lookup return two rows?＋
Some source labels repeat; every matching row is shown.
Does the result guarantee fit?＋
No. Length and label conversion do not capture width or product-specific fit.