225/65R18 vs 255/60R18
255/60R18 is taller than 225/65R18 by 1.80% — a diameter difference of 0.53″.
What changes between 225/65R18 and 255/60R18
Switching from 225/65R18 to 255/60R18 changes overall diameter by +1.80%, a taller tire by 0.53 inches. This lands inside the ±3% fitment safe zone, so most vehicles will accept the swap without rubbing, speedometer recalibration, or ABS/TPMS complications. Section width moves by +1.18″ (225mm → 255mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.26″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -12, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.2 mph. Both sizes share the same 18″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 225/65R18 | 255/60R18 |
|---|---|---|
| Overall diameter | 29.52″ | 30.05″ |
| Section width | 8.86″ (225 mm) | 10.04″ (255 mm) |
| Sidewall height | 5.76″ (65%) | 6.02″ (60%) |
| Rim diameter | 18″ | 18″ |
| Circumference | 92.73″ | 94.4″ |
| Revs per mile | 683 | 671 |
Interactive comparison
275/65R18 or "33" for inch aliases225/65R18
- Diameter
- 29.52″ / 749.7mm
- Section Width
- 8.86″
- Sidewall
- 5.76″ / 146.25mm
- Circumference
- 92.73″
- Revs/Mile
- 683
255/60R18
- Diameter
- 30.05″ / 763.2mm
- Section Width
- 10.04″
- Sidewall
- 6.02″ / 153mm
- Circumference
- 94.4″
- Revs/Mile
- 671
Speedometer & Diameter Impact
Wider tire — verify wheel widthAt an indicated 60 mph, your actual speed is 61.08 mph (98.3 km/h). Your speedometer reads 1.80% low versus actual speed.