We've created a table that converts all of the standard sized tires to radial and metric size equivalents.
Tractor Tire Conversion Chart
| Standard Size | Radial Size | Metric Size |
| 11.2X20 | 11.2R20 | 280/85R20 |
| 12.4X20 | 12.4R20 | 320/85R20 |
| 9.5X24 | 9.5R24 | 250/85R24 |
| 11.2X24 | 11.2R24 | 280/85R24 |
| 12.4X24 | 12.4R24 | 320/85R24 |
| 13.6X24 | 13.6R24 | 340/85R24 |
| 14.9X24 | 14.9R24 | 380/85R24 |
| 16.9X24 | 16.9R24 | 420/85R24 |
| 18.4X26 | 18.4R26 | 420/85R26 |
| 11.2X28 | 11.2R28 | 280/85R28 |
| 12.4X28 | 12.4R28 | 320/85R28 |
| 13.6X28 | 13.6R28 | 340/85R28 |
| 14.9X28 | 14.9R28 | 380/85R28 |
| 16.9X28 | 16.9R28 | 420/85R28 |
| 14.9X30 | 14.9R30 | 380/85R30 |
| 16.9X30 | 16.9R30 | 420/85R30 |
| 420/90R30 | ||
| 18.4X30 | 18.4R30 | 460/85R30 |
| 12.4X32 | 12.4R32 | 320/85R32 |
| 12.4X34 | 12.4R34 | 320/85R34 |
| 14.9X34 | 14.9R34 | 380/85R34 |
| 16.9X34 | 16.9R34 | 420/85R34 |
| 18.4X34 | 18.4R34 | 460/85R34 |
| 20.8X34 | 20.8R34 | 520/85R34 |
| 12.4X36 | 12.4R36 | 320/85R36 |
| 13.6X36 | 13.6R36 | 340/85R36 |
| 13.6X38 | 13.6R38 | 340/85R38 |
| 14.9X38 | 14.9R38 | 380/85R38 |
| 16.9X38 | 16.9R38 | 420/85R38 |
| 18.4X38 | 18.4R38 | 460/85R38 |
| 20.8X38 | 20.8R38 | 520/85R38 |
| 18.4X42 | 18.4R42 | 460/85R42 |
| 20.8X42 | 20.8R42 | 520/85R42 |
| 20.8X46 | 20.8R46 | 520/85R46 |
