225/60R18 vs 285/50R18
285/50R18 is taller than 225/60R18 by 2.06% — a diameter difference of 0.59″.
What changes between 225/60R18 and 285/50R18
Switching from 225/60R18 to 285/50R18 changes overall diameter by +2.06%, a taller tire by 0.59 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 +2.36″ (225mm → 285mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.30″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -14, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.3 mph. Both sizes share the same 18″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 225/60R18 | 285/50R18 |
|---|---|---|
| Overall diameter | 28.63″ | 29.22″ |
| Section width | 8.86″ (225 mm) | 11.22″ (285 mm) |
| Sidewall height | 5.31″ (60%) | 5.61″ (50%) |
| Rim diameter | 18″ | 18″ |
| Circumference | 89.94″ | 91.8″ |
| Revs per mile | 704 | 690 |
Interactive comparison
275/65R18 or "33" for inch aliases225/60R18
- Diameter
- 28.63″ / 727.2mm
- Section Width
- 8.86″
- Sidewall
- 5.31″ / 135mm
- Circumference
- 89.94″
- Revs/Mile
- 704
285/50R18
- Diameter
- 29.22″ / 742.2mm
- Section Width
- 11.22″
- Sidewall
- 5.61″ / 142.5mm
- Circumference
- 91.8″
- Revs/Mile
- 690
Speedometer & Diameter Impact
Wider tire — verify wheel widthAt an indicated 60 mph, your actual speed is 61.24 mph (98.55 km/h). Your speedometer reads 2.06% low versus actual speed.