275/45R20 vs 265/50R20
265/50R20 is taller than 275/45R20 by 2.32% — a diameter difference of 0.69″.
What changes between 275/45R20 and 265/50R20
Switching from 275/45R20 to 265/50R20 changes overall diameter by +2.32%, a taller tire by 0.69 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 +0.35″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -15, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.5 mph. Both sizes share the same 20″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 275/45R20 | 265/50R20 |
|---|---|---|
| Overall diameter | 29.74″ | 30.43″ |
| Section width | 10.83″ (275 mm) | 10.43″ (265 mm) |
| Sidewall height | 4.87″ (45%) | 5.22″ (50%) |
| Rim diameter | 20″ | 20″ |
| Circumference | 93.44″ | 95.61″ |
| Revs per mile | 678 | 663 |
Interactive comparison
275/65R18 or "33" for inch aliases275/45R20
- Diameter
- 29.74″ / 755.5mm
- Section Width
- 10.83″
- Sidewall
- 4.87″ / 123.75mm
- Circumference
- 93.44″
- Revs/Mile
- 678
265/50R20
- Diameter
- 30.43″ / 773mm
- Section Width
- 10.43″
- Sidewall
- 5.22″ / 132.5mm
- Circumference
- 95.61″
- Revs/Mile
- 663
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 61.39 mph (98.8 km/h). Your speedometer reads 2.32% low versus actual speed.