235/60R18 Tire Size
235/60R18 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 235/60R18 tire size breaks down as: 235 mm section width, 60% aspect ratio, and a 18-inch rim. Below are its real, calculated dimensions.
235/60R18 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 29.1 in (739 mm) |
| Sidewall height | 5.6 in (141 mm) |
| Circumference | 91.4 in (2322 mm) |
| Revolutions per mile | 693 |
Typical Fitment
235/60R18 is most often found on midsize SUVs. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 235/60R18, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 245/60R18 | 29.57 in | +1.6% |
| 245/50R19 | 28.65 in | -1.6% |
| 255/45R20 | 29.04 in | -0.2% |
Speedometer Note
If you fit a 245/60R18 instead of 235/60R18, 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 235/60R18 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 235/60R18 mean?
235/60R18 means a 235 mm wide tire with a 60% sidewall aspect ratio mounted on a 18-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 235/60R18?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 235/60R18 are 245/60R18, 245/50R19, 255/45R20.
Will 235/60R18 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.