A shoe size converter estimates the equivalent shoe size in another sizing system, such as EU to US. Formula: to EU: uk/us m +33, us w +31, eu unchanged. from EU: reverse offsets. Approximate adult offsets only. EU 42 is about US men’s 9 or US women’s 11.
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How to use the shoe size converter
- Enter your size.
- Choose the system you are converting from.
- Choose the system you want.
- Read the estimated size, then check the brand chart.
How the shoe size converter works
The shoe size converter uses simple offsets from European (EU) sizes. It treats US men’s size as EU minus 33, US women’s size as EU minus 31, and UK size as EU minus 34, one size below US men’s. It converts your size to EU first and then to the target system. EU 42 becomes US men’s 9, US women’s 11 and UK 8. The offsets are an approximation: real brands and charts differ, often by half a size.
A note on UK sizes
The shoe size converter follows the common retail rule that a UK size is one below the US men’s size and two below the US women’s size, as in the Foot Locker UK size guide, where US men’s 9 is UK 8 and EU 42. Some American retailers use a half-size gap instead, so a US men’s 9 can appear as UK 8.5. Check the brand’s own chart before buying.
Shoe size converter worked example
A shopper who wears EU 42 enters 42 and chooses EU to US men’s. The tool subtracts 33 and shows US men’s 9. Choosing US women’s instead subtracts 31 and shows 11. Going the other way, a US women’s 8 is EU 39. The table shows a range of sizes using the tool’s offsets.
| EU | US men | US women | UK (tool) |
|---|---|---|---|
| 40 | 7 | 9 | 6 |
| 41 | 8 | 10 | 7 |
| 42 | 9 | 11 | 8 |
| 43 | 10 | 12 | 9 |
| 44 | 11 | 13 | 10 |
| 45 | 12 | 14 | 11 |
Why sizing systems differ
Shoe sizes grew up separately in different countries. UK and US sizes count in steps of one third of an inch, about 8.47 mm, but start from different zero points. EU sizes, also called Paris points, step by two thirds of a centimeter, about 6.67 mm. Because the steps differ, no single offset is exactly right across the whole range, and rounding to whole or half sizes adds further error.
Measure your foot
The most reliable approach is to measure. Stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe, and measure the distance in centimeters or inches. Measure both feet in the afternoon, when feet are slightly larger, and use the longer one. Many brands publish a chart from foot length to size, and some use a Mondopoint size, which is simply the foot length in millimeters.
Length is not the only factor
Width, arch height and the shape of the toe box all affect fit. Running shoes are often bought half a size up to leave room for swelling. Children’s sizes use a separate scale, so do not use adult offsets for kids. Use the shoe size converter as a starting point and confirm with the seller’s size chart and return policy.
Buying shoes online with a shoe size converter
When you buy from a retailer in another country, convert your usual size with the shoe size converter, then compare the result with the foot-length column of the brand’s chart. If the two disagree, trust the foot length. Read reviews for comments such as runs small or runs large, and check that free returns or exchanges are available before ordering several sizes. Half sizes are common in US and UK sizing but less so in EU sizing, so you may need to round up.
Tips
- Check the brand’s own size chart.
- Measure feet later in the day.
- Allow about a thumb’s width at the toe.
- Expect UK sizes about one below US men’s.
Related converters and calculators
Related calculators:
- Inches to cm: length
- cm to feet: height
- Length converter: units
- Unit converter: all units
Sources
NIST: SI units – length; NIST: Approximate conversions from U.S. customary measures to metric; Foot Locker UK: EU, UK and US shoe size guide.
Formula and method
to EU: uk/us_m +33, us_w +31, eu unchanged. from EU: reverse offsets. Approximate adult offsets only.
Documented EU-pivot sketch in live JS. Not Mondopoint lab lasts; brands vary.
Questions about this calculator
What US size is EU 42?
About US men’s 9 or US women’s 11.
Are UK and US sizes the same?
No. UK is about one size below US men’s and two below US women’s; this tool uses that offset.
How do I measure my foot?
Heel to longest toe on paper, in the afternoon.
What is Mondopoint?
Foot length in millimeters.
Does it work for children?
No, kids use a different scale.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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