275/65R20 Tire Size
275/65R20 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 275/65R20 tire size breaks down as: 275 mm section width, 65% aspect ratio, and a 20-inch rim. Below are its real, calculated dimensions.
275/65R20 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 34.1 in (865 mm) |
| Sidewall height | 7.0 in (179 mm) |
| Circumference | 107.0 in (2719 mm) |
| Revolutions per mile | 592 |
Typical Fitment
275/65R20 is most often found on SUVs and half-ton pickups. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 275/65R20, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 285/65R20 | 34.59 in | +1.5% |
| 285/60R21 | 34.46 in | +1.1% |
| 295/50R22 | 33.61 in | -1.4% |
Speedometer Note
If you fit a 285/65R20 instead of 275/65R20, the diameter changes by +1.5%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 59 mph. A shorter tire has the opposite effect, so the gauge reads high.
Use the tire calculator to compare 275/65R20 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 275/65R20 mean?
275/65R20 means a 275 mm wide tire with a 65% sidewall aspect ratio mounted on a 20-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 275/65R20?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 275/65R20 are 285/65R20, 285/60R21, 295/50R22.
Will 275/65R20 affect my speedometer?
Only if it differs in diameter from your original size. A taller tire reads low; a shorter tire reads high. Compare the two sizes with the calculator to find the percentage.