Tractor-Size › Radial ↔ bias-ply tire equivalents
Radial ↔ bias-ply tire equivalents
Metric radial sizes and their bias-ply (tube type) equivalents. Example: 380/85R28 = 14.9/13-28.
| Radial 85 series | Bias ply (tube type) | Radial 70 series (wider) | Inch radial | Outside dia. |
|---|---|---|---|---|
| 280/85R24 | 11.2-24 | 320/70R24 | 11.2R24 | 1,086 mm |
| 320/85R24 | 12.4/11-24 | 360/70R24 | 12.4R24 | 1,154 mm |
| 340/85R24 | 13.6/12-24 | 380/70R24 | 13.6R24 | 1,188 mm |
| 380/85R24 | 14.9/13-24 | 420/70R24 | 14.9R24 | 1,256 mm |
| 620/75R26 | 23.1-26 | – | 23.1R26 | 1,573 mm |
| 280/85R28 | 11.2/10-28 | 320/70R28 | 11.2R28 | 1,187 mm |
| 320/85R28 | 12.4/11-28 | 360/70R28 | 12.4R28 | 1,255 mm |
| 340/85R28 | 13.6/12-28 | 380/70R28 | 13.6R28 | 1,287 mm |
| 380/85R28 | 14.9/13-28 | 420/70R28 | 14.9R28 | 1,350 mm |
| 420/85R28 | 16.9/14-28 | 480/70R28 | 16.9R28 | 1,425 mm |
| 380/85R30 | 14.9/13-30 | 420/70R30 | 14.9R30 | 1,404 mm |
| 420/85R30 | 16.9/14-30 | 480/70R30 | 16.9R30 | 1,475 mm |
| 460/85R30 | 18.4/15-30 | 520/70R30 | 18.4R30 | 1,544 mm |
| 620/75R30 | 23.1-30 | – | 23.1R30 | 1,678 mm |
| 320/85R32 | 12.4/11-32 | – | 12.4R32 | 1,357 mm |
| 420/85R34 | 16.9/14-34 | 480/70R34 | 16.9R34 | 1,578 mm |
| 460/85R34 | 18.4/15-34 | 520/70R34 | 18.4R34 | 1,646 mm |
| 320/85R36 | 12.4/11-36 | – | 12.4R36 | 1,458 mm |
| 340/85R36 | 13.6/12-36 | – | 13.6R36 | 1,492 mm |
| 340/85R38 | 13.6/12-38 | – | 13.6R38 | 1,540 mm |
| 420/85R38 | 16.9/14-38 | 480/70R38 | 16.9R38 | 1,675 mm |
| 460/85R38 | 18.4-38 | 520/70R38 | 18.4R38 | 1,747 mm |
| 520/85R38 | 20.8-38 | 580/70R38 | 20.8R38 | 1,849 mm |
Tubeless tires can run with a tube; moving from tube type to tubeless usually needs a different rim.