275/50R20 vs 265/55R20
265/55R20 is taller than 275/50R20 by 2.11% — a diameter difference of 0.65″.
What changes between 275/50R20 and 265/55R20
Switching from 275/50R20 to 265/55R20 changes overall diameter by +2.11%, a taller tire by 0.65 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″ (275mm → 265mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.33″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -13, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.4 mph. Both sizes share the same 20″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 275/50R20 | 265/55R20 |
|---|---|---|
| Overall diameter | 30.83″ | 31.48″ |
| Section width | 10.83″ (275 mm) | 10.43″ (265 mm) |
| Sidewall height | 5.41″ (50%) | 5.74″ (55%) |
| Rim diameter | 20″ | 20″ |
| Circumference | 96.85″ | 98.89″ |
| Revs per mile | 654 | 641 |
Interactive comparison
275/65R18 or "33" for inch aliases275/50R20
- Diameter
- 30.83″ / 783mm
- Section Width
- 10.83″
- Sidewall
- 5.41″ / 137.5mm
- Circumference
- 96.85″
- Revs/Mile
- 654
265/55R20
- Diameter
- 31.48″ / 799.5mm
- Section Width
- 10.43″
- Sidewall
- 5.74″ / 145.75mm
- Circumference
- 98.89″
- Revs/Mile
- 641
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 61.26 mph (98.6 km/h). Your speedometer reads 2.11% low versus actual speed.