EU to US shoe size converter
A men's US 9 is an EU 42, or 41.91 exactly, both matching a last of 27.94 cm. Enter an adult size, pick the direction and men's or women's sizing, and get the number to order abroad. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Size
- 9
- From
- Us
- To
- Eu
- Gender
- Men
- Converted size
- 42
- Converted exact
- 41.91
- Us
- 9
- Eu
- 41.91
This EU to US shoe size converter turns an adult European or American shoe size into the matching size in the other system, using the wearer's gender so men's and women's US lasts are not mixed. Shoppers use it before ordering from an overseas store, travelers use it when a boutique tags only EU numbers, and support desks use it when a return form asks for the other region's size. The engine maps the input through last length in inches: US men's and women's Brannock-style identities plus the EU Paris-point rule that one size equals two thirds of a centimetre.
What EU and US shoe sizes mean for you
Converting a shoe size between the European (EU) and United States (US) systems answers a shopping question: if you wear a given adult size in one region, what number should you ask for in the other. The two systems do not share a zero point and they do not share a step. US adult sizes are last-length marks on the Brannock scale, with a different offset for men and for women so that a women's US 8 is not the same last as a men's US 8.
EU sizes are Paris points: each whole size is two thirds of a centimetre of last length, and that scale does not change with gender. This converter therefore always asks for gender, maps the input size onto last length in inches, and then projects that length onto the other system. If you need UK, centimetre last length, or a four-scale table, use a broader shoe-size helper; this page is the EU-versus-US landing.
Where EU–US shoe conversion fits in shopping, travel, and software
People meet EU-to-US shoe conversion when a European web shop lists 42 and a US return portal asks for the American size, when a traveler tries on a pair tagged only in Paris points, or when a teacher asks students to convert a last length into both regional tags. Shoppers can pre-check a men's US 9 against its EU neighbour before they treat an international checkout as a sunk cost, and customer-care teams can answer “what is my EU size in US?”
without a laminated chart that disagrees with the next brand. Contest and homework practice often needs a fast, offline source of conversions so solutions can be checked without a paper size chart under time pressure. Product and education tools use the split when a learner types a size and the interface must show a clean wearable tag beside the exact last length.
Pair it with clothing or bra-size helpers when you are assembling a small lab of free, deterministic apparel-planning tools.
What you can do with it
Order shoes from an overseas store
Convert a known EU or US adult size by gender into the other region's wearable tag before you check out.
Travel and boutique fittings
Turn a Paris-point number on a European box into the matching US size, or the other way around, without a paper chart.
FAQ
What does the EU to US shoe size converter cost?
It is free in your browser on this page.
What happens if the size is outside the supported range?
Published adult ranges are US men 3–16, US women 4–13, EU men 35–50, and EU women 35–46.
Why do you ask for gender if EU sizes are unisex?
EU Paris-point last length does not change with gender, but the paired US Brannock size does. A women's US 8 is a different last from a men's US 8.
Does this include UK sizes or brand-fit differences?
No. This landing converts only EU and US adult sizes. UK, Mondopoint, children's ranges, and brand last-shape slop are out of scope.
Why is the converted size rounded?
Because shoes are sold in whole and half sizes. The exact result, such as 41.91, is rounded to the nearest half size you can actually buy, here EU 42, and both figures are shown.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/life/eu-us-shoe-size \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"size":9,"from":"us","gender":"men"}'const res = await fetch("https://api.kit.forhosting.com/life/eu-us-shoe-size", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"size": 9,
"from": "us",
"gender": "men"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/life/eu-us-shoe-size",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"size": 9,
"from": "us",
"gender": "men"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/life/eu-us-shoe-size", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"size":9,"from":"us","gender":"men"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"size":9,"from":"us","gender":"men"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/life/eu-us-shoe-size", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"size": 9,
"from": "us",
"gender": "men"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "life.eu_us_shoe_size",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
us_men_min | 3 |
us_men_max | 16 |
us_women_min | 4 |
us_women_max | 13 |
eu_men_min | 35 |
eu_men_max | 50 |
eu_women_min | 35 |
eu_women_max | 46 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
A size outside the published adult range is rejected as invalid_input instead of being silently clamped. Run it free in the browser for everyday shopping, or call the API at $0.002 per successful request when a catalog, return desk, or classroom worksheet needs the same conversion.
What EU and US shoe sizes mean and what the response contains
The response echoes the normalized size, from, to, and gender fields, returns converted_size as the nearest half-size you would actually buy, returns converted_exact as the unrounded formula result, and also reports us, eu, last_length_cm, and last_length_in so a spreadsheet can show both the wearable tag and the underlying last. There is no UK scale, no Mondopoint millimetre table, no children's range, and no brand-fit fudge: the engine either applies the closed last-length identities or rejects the input with invalid_input. Rejected cases include a missing size, from, or gender field, a non-finite size, an unknown system or gender token, a request where from and to name the same system, and — this is the product contract — a size outside the published adult range for that system and gender.
How size, from, to, and gender are read so results stay reproducible
Optional leading plus signs and scientific notation on the numeric size are allowed when they parse as finite decimals; embedded spaces, hex prefixes, and non-numeric tokens are rejected with a message that names the field so a bad cell does not become a wrong pair of sneakers. Published adult ranges are US men 3 to 16, US women 4 to 13, EU men 35 to 50, and EU women 35 to 46; half sizes such as 9.5 are welcome inside those bounds. The preferred field for the number on the box is size, but aliases value, sz, and n are accepted so a form, a query string, or a spreadsheet column can reuse the same contract without renaming cells. The source system prefers from, with aliases source, scale, system, and from_system; allowed values are eu and us. The target system prefers to, with aliases target, dest, and to_system; if to is omitted the engine converts to the other system, and if to equals from the request is rejected so a no-op is not billed as a conversion. Gender prefers gender, with aliases sex and wearer; allowed values are men and women because the US last offset depends on that choice. Computation uses ordinary floating-point last-length arithmetic, rounds converted_size to the nearest half, and rounds the exact fields to twelve decimal places so goldens stay stable across runtimes. Pair the free browser run on this page with the priced API when you need that identical mathematical result inside a catalog import or return-desk script without re-implementing the last-length rule yourself.
Where EU–US shoe conversion fits in shopping, travel, and software
Developers call the same contract from scripts to seed deterministic test vectors for footwear calculators, to normalize user-entered sizes before a catalog demo, or to satisfy a product statement that demands a converted_size field rather than a hand-waved guess. On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the mathematical result.
Integration use cases
Catalogs, returns, and test fixtures
Normalize size, from, to, and gender into stable converted_size and last-length fields for product interfaces and continuous-integration assertions.
Technical questions
How is the converted size defined?
The input size is mapped to last length L in inches: US men = 3L−24, US women = 3L−22.5, EU = 1.5·(L·2.54). converted_size is the target size rounded to the nearest half. converted_exact is the unrounded value.