235/55R17 Tire Size
235/55R17 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 235/55R17 tire size breaks down as: 235 mm section width, 55% aspect ratio, and a 17-inch rim. Below are its real, calculated dimensions.
235/55R17 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 27.2 in (690 mm) |
| Sidewall height | 5.1 in (129 mm) |
| Circumference | 85.4 in (2169 mm) |
| Revolutions per mile | 742 |
Typical Fitment
235/55R17 is most often found on midsize sedans and crossovers. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 235/55R17, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 245/55R17 | 27.61 in | +1.6% |
| 245/50R18 | 27.65 in | +1.7% |
| 255/40R19 | 27.03 in | -0.5% |
Speedometer Note
If you fit a 245/55R17 instead of 235/55R17, the diameter changes by +1.6%. 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 235/55R17 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 235/55R17 mean?
235/55R17 means a 235 mm wide tire with a 55% sidewall aspect ratio mounted on a 17-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 235/55R17?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 235/55R17 are 245/55R17, 245/50R18, 255/40R19.
Will 235/55R17 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.