265/35R21 vs 275/35R21
275/35R21 is taller than 265/35R21 by 0.97% — a diameter difference of 0.28″.
What changes between 265/35R21 and 275/35R21
Switching from 265/35R21 to 275/35R21 changes overall diameter by +0.97%, a taller tire by 0.28 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″ (265mm → 275mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.14″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -7, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 65.6 mph. Both sizes share the same 21″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 265/35R21 | 275/35R21 |
|---|---|---|
| Overall diameter | 28.3″ | 28.58″ |
| Section width | 10.43″ (265 mm) | 10.83″ (275 mm) |
| Sidewall height | 3.65″ (35%) | 3.79″ (35%) |
| Rim diameter | 21″ | 21″ |
| Circumference | 88.92″ | 89.78″ |
| Revs per mile | 713 | 706 |
Interactive comparison
275/65R18 or "33" for inch aliases265/35R21
- Diameter
- 28.3″ / 718.9mm
- Section Width
- 10.43″
- Sidewall
- 3.65″ / 92.75mm
- Circumference
- 88.92″
- Revs/Mile
- 713
275/35R21
- Diameter
- 28.58″ / 725.9mm
- Section Width
- 10.83″
- Sidewall
- 3.79″ / 96.25mm
- Circumference
- 89.78″
- Revs/Mile
- 706
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 60.58 mph (97.5 km/h). Your speedometer reads 0.97% low versus actual speed.