What this shoe size converter does
This shoe size converter answers the US to EU shoe size question, and every similar one, in one step. Pick the system you know – US men's, US women's, US kids' C or Y, UK adult or children's, EU, foot length in centimeters or inches, or Mondopoint – type a size, and the other systems appear at once. US men's 9 converts to EU 42, UK 8, US women's 10.5 and a foot length of about 26.4–26.5 cm.
The tool also shows full men's, women's and kids' charts built from the same model, so the converter and the charts never contradict each other. One model cannot match every brand: shoe companies build on their own lasts, and real sizes vary by half a size or more. Treat the results as standard typical values, and use the brand's own chart when there is one.
How to use the converter
- Choose the system you are converting from in Convert from. Pick a foot-length option if you have measured your foot.
- Type the size. Halves can be written 8.5, 8,5, 8 1/2 or 8½, and EU sizes in thirds such as 42 2/3 are accepted. The − and + buttons step half a size at a time, or 0.5 cm, 0.25 in and 5 mm for foot lengths.
- Read the cards. The emphasized card is your input; each card shows the rounded size and the unrounded model value, so you can see when a size sits between two others.
- Copy all sizes copies one line such as "US men's 9 = US women's 10.5 = UK 8 = EU 42 = 26.4 cm foot".
- Open the Men, Women or Kids chart. The row that matches your size is highlighted, and each chart downloads as a CSV file.
When you switch Convert from, the tool carries the same foot across, so changing from US men's 9 to EU fills in 42. Sizes outside a system's normal range show a dash.
US to EU shoe size at a glance
| US men's | US women's | UK | EU |
|---|---|---|---|
| 6 | 7.5 | 5 | 38 |
| 7 | 8.5 | 6 | 39.5 |
| 8 | 9.5 | 7 | 40.5 |
| 9 | 10.5 | 8 | 42 |
| 10 | 11.5 | 9 | 43 |
| 11 | 12.5 | 10 | 44.5 |
| 12 | 13.5 | 11 | 45.5 |
Between US men's 8 and 11, EU is roughly the men's size plus 33; between women's 6 and 9, roughly the women's size plus 30.5. The shortcut drifts at the ends because one US size step (a third of an inch) is longer than one EU step (two-thirds of a centimeter): each US size adds about 1.27 EU sizes.
How shoe sizes are built: the model behind the numbers
Traditional shoe sizes measure the last, the foot-shaped form a shoe is made on, not the foot itself. The last is longer than the foot to leave room for the toes. Each system then counts in its own unit:
- UK and US count in barleycorns of 1/3 inch (about 8.47 mm). Adult UK sizes start a fixed distance above children's sizes, which is why UK children's 13.5 is followed by adult 1.
- EU (the Paris point system) counts in steps of 2/3 cm (about 6.67 mm), starting from zero length.
- Mondopoint (ISO 9407) and Japanese sizes skip the last and state the foot length itself, in millimeters or centimeters.
The converter uses one documented set of formulas for everything:
last length (in) = (UK adult size + 25) ÷ 3
= (UK children's size + 12) ÷ 3
US men's = UK + 1
US women's = UK + 2.5 (US men's + 1.5)
US kids (C and Y) = UK + 0.5
EU = last length (cm) × 1.5
foot length = last length − 1.5 cm
Mondopoint = foot length in mm (5 mm steps); JP = foot length in cm (0.5 steps)
A worked example, US women's 8:
UK = 8 − 2.5 = 5.5
last = (5.5 + 25) ÷ 3 = 10.17 in = 25.82 cm
EU = 25.82 × 1.5 = 38.7, shown as 38.5
foot = 25.82 − 1.5 = 24.3 cm, Mondopoint 245, JP 24.5
The other direction works the same way. EU 42 is a last of 42 × 2/3 = 28 cm, or 11.024 inches. That gives UK 3 × 11.024 − 25 = 8.07, rounded to 8, so US men's 9 and US women's 10.5.
The 1.5 cm allowance and the offsets were chosen so the charts land in the middle of commonly published size charts: EU 42 sits at US men's 9 and UK 8, and US women's 8 at EU 38.5. Published charts disagree with each other by about half a size, especially for women's and kids' sizes, so no single model can match them all.
Women's to men's shoe size
US women's sizes are 1.5 larger than men's for the same foot. Subtract 1.5 to go from women's to men's, and add 1.5 to go the other way: women's 8 is men's 6.5, and men's 9 is women's 10.5. Unisex sneakers are often labeled in men's sizes, so a woman who wears 8 would look for 6.5.
UK and EU sizes have no separate women's scale. A UK 5.5 or an EU 38.5 is the same length whoever wears it, which makes those numbers the safer ones to compare across men's and women's styles. Some brands use a gap of 1 or 2 sizes instead of 1.5, so check their chart for unisex models.
Kids' sizes: C and Y
US children's shoes run from 0C to 13.5C (C for child, covering babies, toddlers and little kids) and continue at 1Y to 7Y (Y for youth, or big kids). UK children's sizes run from 0 to 13.5 and then continue at adult size 1. In this model a US kids' size is half a size above the UK number: 10C is UK 9.5 children's, EU 27.5 and a 16.7 cm foot. Higher up, 4Y is UK 3.5 and EU 36.
Youth sizes overlap with adult sizes. Here, 7Y equals US men's 7.5 and women's 9; many retailers simply call 7Y a men's 7. Children's feet grow quickly, so measure again every few months rather than converting from the last pair.
Measuring your foot
Converting from a measured foot is more reliable than converting from a size printed in another system.
- Put a sheet of paper on a hard floor with one edge against a wall.
- Stand on it in the socks you plan to wear, heel against the wall, with your weight on that foot.
- Mark the end of your longest toe. For children, a second person makes this much easier.
- Measure from the wall to the mark. Do both feet and use the longer one.
- Choose Foot length (cm) or (inches) and enter the number.
Measure late in the day, when feet are at their largest. A foot of 25 cm gives US men's 7.5, but the model value sits between UK 6 and 6.5, and the converter says so. In that case the larger half size is usually the safer choice.
Tips and common mistakes
- UK 8 is not US 8. For men, UK 8 is US 9 in this model (US 8.5 at some brands). For women, UK 5.5 is US 8. Mixing the two is the most common cause of a pair that is a full size off.
- Do not chain conversions. Converting US to UK, then UK to EU, rounds twice. Convert from the original size, or better, from foot length.
- Expect EU half sizes and thirds. Some brands sell EU 42 2/3 or 42.5. The converter accepts thirds and shows the model value, so you can see that EU 42 2/3 is a little over US men's 9.5.
- Mondopoint steps are coarser than half sizes. A 5 mm Mondopoint step is longer than a half size (about 4.2 mm), so two neighboring half sizes sometimes share one Mondopoint number in the charts.
- Length is only half the fit. Width, instep height and the shoe's shape matter too, and this converter covers length only.
Privacy and limitations
Conversions and charts are computed on your device, and the sizes you enter never leave it. The last system and size you used are kept in this browser's local storage, ready for your next visit.
The model covers US men's 3–18, US women's 3–17, US kids' 0C–13.5C and 1Y–7Y, UK 0–13.5 children's and 1–17 adult, EU 15–52, and foot lengths from 8 to 35 cm. It rounds to the nearest half size, 0.1 cm and 5 mm. It is not any brand's official chart, and it does not account for width or for differences between athletic, dress and sandal lasts.
Frequently asked questions
What is EU 42 in US shoe size?
In this converter's model EU 42 is US men's 9, women's 10.5 and UK 8; many sneaker brands label EU 42 as US men's 8.5. In the model an EU 42 last is 28 cm long, which works out to UK 8.07, rounded to 8. If you are between sizes, compare the brand's own chart or convert from your foot length instead, which is about 26.4–26.5 cm for this size.
How do I convert women's shoe sizes to men's?
Subtract 1.5 from the US women's size to get the US men's size, and add 1.5 to go back. A women's 8 is a men's 6.5, and a men's 9 is a women's 10.5. Unisex sneakers are often sold in men's sizes, so this is the conversion to use. UK and EU sizes are the same for men and women, so no conversion is needed there. A few brands use a gap of 1 or 2 sizes.
Are UK and US shoe sizes the same?
No. For the same foot, the UK number is smaller. In the converter's model, US men's is UK plus 1 and US women's is UK plus 2.5, so a UK 6 is a US men's 7 and a US women's 8.5. Children's sizes differ by about half a size: US 10C is UK 9.5. Always check which country a size label refers to before ordering from an overseas shop.
How do I convert my foot length in cm to a US shoe size?
Measure your foot from heel to longest toe, choose Foot length (cm) and type the number. The converter adds a 1.5 cm allowance to get the shoe's last length and converts from there: a 26.5 cm foot is about US men's 9, US women's 10.5, UK 8 and EU 42. If the result is flagged as between two sizes, the larger half size is usually the safer choice.
What is Mondopoint and who uses it?
Mondopoint is a sizing system, defined in ISO 9407, that labels shoes by foot length in millimeters instead of an arbitrary size number. A Mondopoint 265 shoe fits a foot about 265 mm long, roughly US men's 9 or EU 42. It is common for ski and snowboard boots and military footwear. Japanese sizes use the same idea in centimeters, so 26.5 there is the same foot.
Why is my shoe size different between brands?
Each brand designs its own lasts and decides where each size number falls, so the same foot can be a 9 in one brand and a 9.5 in another. Rounding adds more variation: EU sizes are smaller steps than US sizes, so brands round the conversion differently. Use this converter for typical values, then check the brand's chart, especially for running shoes, boots and European sandals.
What do C and Y mean on kids' shoe sizes?
C means child and covers babies, toddlers and little kids, from 0C to 13.5C. Y means youth, or big kids, and runs from 1Y to 7Y; it starts straight after 13.5C. In this model 4Y is UK 3.5 and EU 36, and 7Y is about US men's 7.5 or women's 9. Many retailers simply treat 7Y as a men's 7, which is within the usual half-size spread between brands.