Shoe Size Conversion
Convert a shoe size between US, UK, EU, and JP (Japan) systems. Uses a common adult-unisex reference chart via a European size intermediate.
Last updated: September 2026
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About this calculator
Shoe sizes are not standardized internationally. Each country's system started from a different reference unit — the US and UK from a 'barleycorn' (⅓ inch), the EU from the Paris point (⅔ cm), Japan from the foot length in centimetres — so a straightforward conversion table is the only reliable way to move between them.
This calculator uses a common adult-unisex approximation via EU size as the intermediate: EU ≈ US + 33 (US men's) ≈ UK + 34 ≈ JP + 16. The output rounds to the nearest 0.5 to match the half-size granularity most brands stock. Women's US sizes run about 1.5 above men's US, so if your source size is a women's US size, subtract 1.5 first to get the men's-US equivalent, then convert.
Because these are approximations, the same 'converted size' can fit differently across brands (a Nike US 9 is not the same as an Adidas US 9), and the width designation (D, E, EE for US; F, G, H for UK) adds another dimension the length-only conversion cannot capture. Treat the output as a starting point, not a guarantee, and read the brand's own size chart before ordering.
How to use
Example — US 9 to EU. Enter size = 9, fromSystem = US, toSystem = EU. Result = 9 + 33 = EU 42. That is the typical Continental European size for a US men's 9. Example — UK 8 to JP. Enter size = 8, fromSystem = UK, toSystem = JP. Route via EU: EU = 8 + 34 = 42; JP = 42 − 16 = 26. Result: JP 26 (which means 26 cm foot length, JP's native metric). Verify: a men's UK 8 is roughly a 26 cm foot, which matches. For clothing (as opposed to shoes), see the size-conversion tools under everyday.
Frequently asked questions
Is US women's the same as US men's?
No — US women's sizes run about 1.5 sizes higher than US men's for the same foot length. A US men's 8 is roughly a US women's 9.5. If your source is a women's US size, subtract 1.5 to get the equivalent men's US size, then feed that into the calculator. For children's sizes, no simple offset works — consult a brand-specific size chart.
Why don't the numbers match exactly across brands?
There is no ISO standard for shoe sizing that all manufacturers follow. Even within one country, brands calibrate to different foot models. Nike, Adidas, and New Balance often disagree by half a size for the 'same' US size. The conversion here uses a common average; always cross-reference with the brand's own size chart, and if possible measure your foot in centimetres and use the JP size (which is literally foot length).
How do I measure my foot?
Place your foot on a sheet of paper against a wall, heel touching the wall. Mark the tip of your longest toe on the paper. Measure heel-to-mark in centimetres. That length is your Japanese size directly (round up to the nearest 0.5 cm). Compare left and right feet — they are often different by up to 0.5 cm; buy for the larger.
What about width?
This calculator only handles length. Width designations differ by system: US uses B/D/E/EE (narrow → extra-wide) for men, AA/A/B/D for women; UK uses F/G/H; EU is less standardized. If you have wide or narrow feet, choose a brand that offers width variants — the length conversion is only half the story.