Running Shoe Size Conversion Chart
Shoe sizing varies between brands and regions. This chart converts UK sizes (used by most British retailers) to EU, US men's and US women's equivalents, with the corresponding foot length in centimetres. For running shoes, most experts recommend going half a size up from your everyday shoe to allow for foot swelling during runs.
Full Size Conversion Table
| UK | EU | US Men's | US Women's | Foot Length (cm) |
|---|---|---|---|---|
| 3 | 35.5 | 4 | 5.5 | 22.0 |
| 3.5 | 36 | 4.5 | 6 | 22.5 |
| 4 | 37 | 5 | 6.5 | 23.0 |
| 4.5 | 37.5 | 5.5 | 7 | 23.5 |
| 5 | 38 | 6 | 7.5 | 24.0 |
| 5.5 | 38.5 | 6.5 | 8 | 24.5 |
| 6 | 39.5 | 7 | 8.5 | 25.0 |
| 6.5 | 40 | 7.5 | 9 | 25.5 |
| 7 | 41 | 8 | 9.5 | 26.0 |
| 7.5 | 41.5 | 8.5 | 10 | 26.5 |
| 8 | 42 | 9 | 10.5 | 27.0 |
| 8.5 | 42.5 | 9.5 | 11 | 27.5 |
| 9 | 43 | 10 | 11.5 | 28.0 |
| 9.5 | 44 | 10.5 | 12 | 28.5 |
| 10 | 44.5 | 11 | 12.5 | 29.0 |
| 10.5 | 45 | 11.5 | 13 | 29.5 |
| 11 | 46 | 12 | 13.5 | 30.0 |
| 11.5 | 46.5 | 12.5 | — | 30.5 |
| 12 | 47 | 13 | — | 31.0 |
| 13 | 48 | 14 | — | 32.0 |
| 14 | 49.5 | 15 | — | 33.0 |
Sizes are approximate — there is no universal standard and sizes vary between manufacturers. Always try shoes on or check the brand's specific size chart.
Fitting Tips for Running Shoes
- Thumb's width rule: Leave about a thumb's width (1–1.5 cm) between your longest toe and the front of the shoe.
- Try shoes in the afternoon: Your feet swell during the day, so afternoon sizing more closely matches how your feet feel during a run.
- Wear your running socks: Bring the socks you normally run in when trying on shoes.
- Width matters too: Many brands offer wide (2E) and extra-wide (4E) options. If your foot spills over the insole, try a wider fit.
- Replace every 400–800 km: Midsole cushioning degrades with use, so track your shoe mileage.
Related Calculators
- Shoe & Gear Calculators — tools for shoe replacement tracking, gear checklists and more
Shoe sizing conversions are approximate guidelines. Different brands (Nike, Adidas, ASICS, New Balance, etc.) may size differently even within the same nominal system. When in doubt, measure your foot length in cm and compare to the brand's specific size chart.