About Shoe Size Systems
Four sizing systems dominate the shoe world and none of them agree: US and UK sizes both derive from barleycorn-based lasts but offset differently, US women's runs on its own scale, and EU sizes count in Paris points. Order abroad — or just switch brands — and “your size” becomes a genuine question.
Pick the system you know your size in (or enter your measured foot length in cm — the most reliable input) and get the equivalents across US Men's, US Women's, UK, and EU, plus the underlying foot length. Everything is anchored to the measurement standards rather than one brand's chart.
More everyday conversions live in the Decimal Calculator.
The Conversion Math
Foot length is the bridge between all systems:
US Men = 3 × foot length (in) − 22 (Brannock) UK = US Men − 0.5 US Women= US Men + 1.5 EU ≈ (foot cm + 1.5 cm allowance) × 1.5 (Paris points, ⅔ cm each)
Worked example: a 27.1 cm foot is 10.7 inches — US Men's 10 (3 × 10.67 − 22), UK 9.5, US Women's 11.5, EU 43. The ±half-size disagreements you see between published charts come from brands rounding these same formulas differently.
Full Conversion Chart
Generated by this calculator's formulas — the same math the tool runs:
| US Men | US Women | UK | EU | Foot length |
|---|---|---|---|---|
| 6 | 7.5 | 5.5 | 38 | 23.7 cm |
| 7 | 8.5 | 6.5 | 39 | 24.6 cm |
| 8 | 9.5 | 7.5 | 40.5 | 25.4 cm |
| 9 | 10.5 | 8.5 | 41.5 | 26.2 cm |
| 10 | 11.5 | 9.5 | 43 | 27.1 cm |
| 11 | 12.5 | 10.5 | 44 | 27.9 cm |
| 12 | 13.5 | 11.5 | 45.5 | 28.8 cm |
| 13 | 14.5 | 12.5 | 46.5 | 29.6 cm |
Treat the EU column as ±0.5: European brands round Paris points differently, which is why one chart says EU 42 = US 9 and another says 8.5. The centimeter column is the tiebreaker.
Measuring Your Foot Properly
Stand on paper against a wall, heel touching the wall, and mark the tip of your longest toe (not always the big toe). Measure wall-to-mark in centimeters, do both feet — most people's differ — and size to the LONGER foot. Measure in the evening (feet swell through the day) wearing the socks you'll actually use.
Fit notes the number doesn't capture: width matters as much as length (US systems offer widths from narrow to 4E; EU sizing mostly doesn't), running shoes are commonly bought a half size up for toe splay, and kids' sizes are a separate scale entirely — US kids' sizes restart after 13.5, so a youth 1 follows a kids' 13.