Enter a size like 275/65R20 or 33x12.50R15.
| 275/65R20 | 315/70R17 | Diff | |
|---|---|---|---|
| Diameter | 34.1″ | 34.4″ | +0.8% |
| Width | 10.8″ | 12.4″ | +14.5% |
| Sidewall | 7.0″ | 8.7″ | |
| Circumference | 107.0″ | 108.0″ | |
| Revs / mile | 592 | 587 |
At 60 on the speedometer, actual speed is 60.5 mph (+0.8% diameter).