Does the Nike React Infinity Run 4 Run Big or Small?
The Nike React Infinity Run 4 (Running) runs true to size with a wide toe box. See the US/UK/EU/CM conversion chart and what size to order.
How the React Infinity Run 4 fits
The Nike React Infinity Run 4 (Running) runs true to size. Compared with a true-to-size sneaker, order your usual size. It has a wide toe box and high arch support, with a flyknit upper that shapes how the fit settles over time.
React Infinity Run 4 fit specs
| Category | Running |
| Length Fit | True to Size |
| Toe Box Profile | Wide |
| Arch Support | High |
| Upper Material | Flyknit |
Size conversion chart
US, UK, EU and centimetre equivalents. Use it alongside the fit note above to land the right size in the React Infinity Run 4.
| US | UK | EU | CM |
|---|---|---|---|
| 4 | 3 | 36 | 22 |
| 4.5 | 3.5 | 36.5 | 22.5 |
| 5 | 4 | 37 | 23 |
| 5.5 | 4.5 | 37.5 | 23.5 |
| 6 | 5 | 38 | 24 |
| 6.5 | 5.5 | 38.5 | 24.5 |
| 7 | 6 | 39 | 25 |
| 7.5 | 6.5 | 40 | 25.5 |
| 8 | 7 | 41 | 26 |
| 8.5 | 7.5 | 41.5 | 26.5 |
| 9 | 8 | 42 | 27 |
| 9.5 | 8.5 | 42.5 | 27.5 |
| 10 | 9 | 43 | 28 |
| 10.5 | 9.5 | 44 | 28.5 |
| 11 | 10 | 44.5 | 29 |
| 11.5 | 10.5 | 45 | 29.5 |
| 12 | 11 | 46 | 30 |
| 12.5 | 11.5 | 46.5 | 30.5 |
| 13 | 12 | 47 | 31 |
| 13.5 | 12.5 | 47.5 | 31.5 |
| 14 | 13 | 48 | 32 |
| 14.5 | 13.5 | 48.5 | 32.5 |
| 15 | 14 | 49 | 33 |
Frequently asked questions
Does the Nike React Infinity Run 4 run big or small?
The Nike React Infinity Run 4 runs true to size. Compared with a true-to-size sneaker, order your usual size.
What size should I get in the Nike React Infinity Run 4?
If you normally wear a US 10, target a US 10 in the React Infinity Run 4. A US 9 foot maps to about US 9 and a US 11 to about US 11, because the model runs true to size.
Is the Nike React Infinity Run 4 wide or narrow?
It has a wide toe box with extra room across the forefoot. Upper material is flyknit, which affects how much it gives over time.
What kind of arch support does the Nike React Infinity Run 4 have?
Arch support is rated high on the React Infinity Run 4 (Running). Expect a structured, cushioned ride.
Compare the React Infinity Run 4 to another shoe
Select both shoes to see your sizing verdict
| Spec | Nike React Infinity Run 4 | Shoe B |
|---|---|---|
| Length Fit | True to Size | — |
| Toe Box Profile | Wide | — |
| Arch Support | High | — |
| Upper Material | Flyknit | — |