245/45R18 Tire Size
Dimensions of a 245/45R18 tire in inches and millimeters, with equivalent and plus sizes.
245/45R18 dimensions
A 245/45R18 tire is 245 mm wide with a sidewall that is 45% of the width (110 mm), mounted on a 18-inch rim. Its overall diameter is about 26.68 inches (678 mm), so it is roughly a 26.7-inch tall tire.
| Overall diameter | 26.68 in | 678 mm |
|---|---|---|
| Section width | 9.65 in | 245 mm |
| Sidewall height | 4.34 in | 110.2 mm |
| Rim diameter | 18 in | 457 mm |
| Circumference | 83.8 in | 2129 mm |
| Revolutions | 756 per mile | 470 per km |
Equivalent sizes on a 18-inch rim
These sizes stay within ±3% of the 245/45R18 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 |
|---|---|---|---|
| 225/50R18 | 26.86 in | 682 mm | +0.7% |
| 265/40R18 | 26.35 in | 669 mm | -1.3% |
| 235/45R18 | 26.33 in | 669 mm | -1.3% |
| 255/45R18 | 27.04 in | 687 mm | +1.3% |
| 235/50R18 | 27.25 in | 692 mm | +2.1% |
| 255/40R18 | 26.03 in | 661 mm | -2.4% |
| 225/45R18 | 25.97 in | 660 mm | -2.7% |
| 265/45R18 | 27.39 in | 696 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 |
|---|---|---|---|
| 245/40R19 | 26.72 in | 679 mm | +0.1% |
| 245/50R17 | 26.65 in | 677 mm | -0.1% |
| 275/45R17 | 26.74 in | 679 mm | +0.2% |
| 245/35R20 | 26.75 in | 680 mm | +0.3% |
| 275/35R19 | 26.58 in | 675 mm | -0.4% |
| 275/30R20 | 26.50 in | 673 mm | -0.7% |
| 235/35R20 | 26.48 in | 672 mm | -0.8% |
| 235/40R19 | 26.40 in | 671 mm | -1.0% |
| 265/45R17 | 26.39 in | 670 mm | -1.1% |
| 255/35R20 | 27.03 in | 686 mm | +1.3% |
Compare 245/45R18 with another size →
Frequently asked questions
How tall is a 245/45R18 tire?
About 26.68 inches (678 mm) in overall diameter.
How wide is a 245/45R18 tire?
The section width is 245 mm, about 9.6 inches.
What size can replace 245/45R18?
On the same rim, 225/50R18 is the closest size (+0.7% diameter). Use only sizes approved for your vehicle.
How many revolutions per mile does a 245/45R18 tire make?
About 756 revolutions per mile (470 per km).
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