215/50R18 vs 225/50R18
225/50R18 is taller than 215/50R18 by 1.49% — a diameter difference of 0.40″.
What changes between 215/50R18 and 225/50R18
Switching from 215/50R18 to 225/50R18 changes overall diameter by +1.49%, a taller tire by 0.40 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 +0.40″ (215mm → 225mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.20″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -11, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.0 mph. Both sizes share the same 18″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 215/50R18 | 225/50R18 |
|---|---|---|
| Overall diameter | 26.46″ | 26.86″ |
| Section width | 8.46″ (215 mm) | 8.86″ (225 mm) |
| Sidewall height | 4.23″ (50%) | 4.43″ (50%) |
| Rim diameter | 18″ | 18″ |
| Circumference | 83.14″ | 84.38″ |
| Revs per mile | 762 | 751 |
Interactive comparison
275/65R18 or "33" for inch aliases215/50R18
- Diameter
- 26.46″ / 672.2mm
- Section Width
- 8.46″
- Sidewall
- 4.23″ / 107.5mm
- Circumference
- 83.14″
- Revs/Mile
- 762
225/50R18
- Diameter
- 26.86″ / 682.2mm
- Section Width
- 8.86″
- Sidewall
- 4.43″ / 112.5mm
- Circumference
- 84.38″
- Revs/Mile
- 751
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 60.89 mph (98 km/h). Your speedometer reads 1.49% low versus actual speed.