235/45R18 Tire Size
Dimensions of a 235/45R18 tire in inches and millimeters, with equivalent and plus sizes.
235/45R18 dimensions
A 235/45R18 tire is 235 mm wide with a sidewall that is 45% of the width (106 mm), mounted on a 18-inch rim. Its overall diameter is about 26.33 inches (669 mm), so it is roughly a 26.3-inch tall tire.
| Overall diameter | 26.33 in | 669 mm |
|---|---|---|
| Section width | 9.25 in | 235 mm |
| Sidewall height | 4.16 in | 105.8 mm |
| Rim diameter | 18 in | 457 mm |
| Circumference | 82.7 in | 2101 mm |
| Revolutions | 766 per mile | 476 per km |
Equivalent sizes on a 18-inch rim
These sizes stay within ±3% of the 235/45R18 diameter on the same rim — the range most tire shops use. Not every size is made in every tire model, and only sizes approved for your vehicle (with the right load and speed rating) should be fitted.
| Size | Diameter | mm | Difference |
|---|---|---|---|
| 215/50R18 | 26.46 in | 672 mm | +0.5% |
| 255/40R18 | 26.03 in | 661 mm | -1.1% |
| 225/45R18 | 25.97 in | 660 mm | -1.3% |
| 245/45R18 | 26.68 in | 678 mm | +1.3% |
| 225/50R18 | 26.86 in | 682 mm | +2.0% |
| 245/40R18 | 25.72 in | 653 mm | -2.3% |
| 215/45R18 | 25.62 in | 651 mm | -2.7% |
| 255/45R18 | 27.04 in | 687 mm | +2.7% |
Plus and minus sizes
Changing the rim size? These options on 17-, 19- and 20-inch rims keep the overall diameter within ±3%.
| Size | Diameter | mm | Difference |
|---|---|---|---|
| 265/35R19 | 26.30 in | 668 mm | -0.1% |
| 265/45R17 | 26.39 in | 670 mm | +0.2% |
| 265/30R20 | 26.26 in | 667 mm | -0.3% |
| 235/40R19 | 26.40 in | 671 mm | +0.3% |
| 235/50R17 | 26.25 in | 667 mm | -0.3% |
| 225/35R20 | 26.20 in | 666 mm | -0.5% |
| 235/35R20 | 26.48 in | 672 mm | +0.6% |
| 225/40R19 | 26.09 in | 663 mm | -0.9% |
| 255/45R17 | 26.04 in | 661 mm | -1.1% |
| 255/35R19 | 26.03 in | 661 mm | -1.1% |
Compare 235/45R18 with another size →
Frequently asked questions
How tall is a 235/45R18 tire?
About 26.33 inches (669 mm) in overall diameter.
How wide is a 235/45R18 tire?
The section width is 235 mm, about 9.3 inches.
What size can replace 235/45R18?
On the same rim, 215/50R18 is the closest size (+0.5% diameter). Use only sizes approved for your vehicle.
How many revolutions per mile does a 235/45R18 tire make?
About 766 revolutions per mile (476 per km).
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