18-inch tire sizes
64 common 18-inch sizes, from 215/35R18 at 23.93 in to 37x13.50R18 at 37.00 in overall diameter, sorted shortest to tallest below.
The median 18-inch size in this list by overall diameter is 275/45R18 at 27.74 in, turning 727 times per mile; 4 sizes are flotation sizes.
Section widths run from 205 mm to 343 mm, and the most frequent aspect ratio here is 40% (10 sizes).
| Size | Diameter | Width | Sidewall | Rev/mile |
|---|---|---|---|---|
| 215/35R18 | 23.93 in | 8.46 in | 2.96 in | 843 |
| 225/35R18 | 24.20 in | 8.86 in | 3.10 in | 833 |
| 205/40R18 | 24.46 in | 8.07 in | 3.23 in | 825 |
| 235/35R18 | 24.48 in | 9.25 in | 3.24 in | 824 |
| 245/35R18 | 24.75 in | 9.65 in | 3.38 in | 815 |
| 215/40R18 | 24.77 in | 8.46 in | 3.39 in | 814 |
| 255/35R18 | 25.03 in | 10.04 in | 3.51 in | 806 |
| 225/40R18 | 25.09 in | 8.86 in | 3.54 in | 804 |
| 265/35R18 | 25.30 in | 10.43 in | 3.65 in | 797 |
| 235/40R18 | 25.40 in | 9.25 in | 3.70 in | 794 |
| 275/35R18 | 25.58 in | 10.83 in | 3.79 in | 788 |
| 215/45R18 | 25.62 in | 8.46 in | 3.81 in | 787 |
| 245/40R18 | 25.72 in | 9.65 in | 3.86 in | 784 |
| 285/35R18 | 25.85 in | 11.22 in | 3.93 in | 780 |
| 225/45R18 | 25.97 in | 8.86 in | 3.99 in | 777 |
| 255/40R18 | 26.03 in | 10.04 in | 4.02 in | 775 |
| 295/35R18 | 26.13 in | 11.61 in | 4.06 in | 772 |
| 235/45R18 | 26.33 in | 9.25 in | 4.16 in | 766 |
| 265/40R18 | 26.35 in | 10.43 in | 4.17 in | 765 |
| 215/50R18 | 26.46 in | 8.46 in | 4.23 in | 762 |
| 275/40R18 | 26.66 in | 10.83 in | 4.33 in | 756 |
| 245/45R18 | 26.68 in | 9.65 in | 4.34 in | 756 |
| 225/50R18 | 26.86 in | 8.86 in | 4.43 in | 751 |
| 285/40R18 | 26.98 in | 11.22 in | 4.49 in | 748 |
| 255/45R18 | 27.04 in | 10.04 in | 4.52 in | 746 |
| 235/50R18 | 27.25 in | 9.25 in | 4.63 in | 740 |
| 295/40R18 | 27.29 in | 11.61 in | 4.65 in | 739 |
| 215/55R18 | 27.31 in | 8.46 in | 4.66 in | 738 |
| 265/45R18 | 27.39 in | 10.43 in | 4.69 in | 736 |
| 245/50R18 | 27.65 in | 9.65 in | 4.82 in | 730 |
| 225/55R18 | 27.74 in | 8.86 in | 4.87 in | 727 |
| 275/45R18 | 27.74 in | 10.83 in | 4.87 in | 727 |
| 255/50R18 | 28.04 in | 10.04 in | 5.02 in | 719 |
| 285/45R18 | 28.10 in | 11.22 in | 5.05 in | 718 |
| 235/55R18 | 28.18 in | 9.25 in | 5.09 in | 716 |
| 265/50R18 | 28.43 in | 10.43 in | 5.22 in | 709 |
| 245/55R18 | 28.61 in | 9.65 in | 5.31 in | 705 |
| 225/60R18 | 28.63 in | 8.86 in | 5.31 in | 704 |
| 255/55R18 | 29.04 in | 10.04 in | 5.52 in | 694 |
| 235/60R18 | 29.10 in | 9.25 in | 5.55 in | 693 |
| 245/60R18 | 29.57 in | 9.65 in | 5.79 in | 682 |
| 275/55R18 | 29.91 in | 10.83 in | 5.95 in | 674 |
| 235/65R18 | 30.03 in | 9.25 in | 6.01 in | 672 |
| 255/60R18 | 30.05 in | 10.04 in | 6.02 in | 671 |
| 265/60R18 | 30.52 in | 10.43 in | 6.26 in | 661 |
| 245/65R18 | 30.54 in | 9.65 in | 6.27 in | 660 |
| 275/60R18 | 30.99 in | 10.83 in | 6.50 in | 651 |
| 255/65R18 | 31.05 in | 10.04 in | 6.53 in | 650 |
| 285/60R18 | 31.46 in | 11.22 in | 6.73 in | 641 |
| 265/65R18 | 31.56 in | 10.43 in | 6.78 in | 639 |
| 255/70R18 | 32.06 in | 10.04 in | 7.03 in | 629 |
| 275/65R18 | 32.07 in | 10.83 in | 7.04 in | 629 |
| 285/65R18 | 32.59 in | 11.22 in | 7.29 in | 619 |
| 265/70R18 | 32.61 in | 10.43 in | 7.30 in | 619 |
| 33x12.50R18 | 33.00 in | 12.50 in | 7.50 in | 611 |
| 275/70R18 | 33.16 in | 10.83 in | 7.58 in | 608 |
| 285/70R18 | 33.71 in | 11.22 in | 7.85 in | 598 |
| 295/70R18 | 34.26 in | 11.61 in | 8.13 in | 589 |
| 305/70R18 | 34.81 in | 12.01 in | 8.41 in | 579 |
| 285/75R18 | 34.83 in | 11.22 in | 8.42 in | 579 |
| 35x12.50R18 | 35.00 in | 12.50 in | 8.50 in | 576 |
| 315/70R18 | 35.36 in | 12.40 in | 8.68 in | 570 |
| 37x12.50R18 | 37.00 in | 12.50 in | 9.50 in | 545 |
| 37x13.50R18 | 37.00 in | 13.50 in | 9.50 in | 545 |
Common 18-inch comparisons
- 215/35R18 vs 225/35R18 (+1.15%)
- 215/35R18 vs 235/35R18 (+2.30%)
- 215/35R18 vs 215/40R18 (+3.54%)
- 225/35R18 vs 235/35R18 (+1.14%)
- 225/35R18 vs 245/35R18 (+2.28%)
- 225/35R18 vs 225/40R18 (+3.66%)
- 205/40R18 vs 215/40R18 (+1.29%)
- 205/40R18 vs 225/40R18 (+2.58%)
- 235/35R18 vs 245/35R18 (+1.13%)
- 235/35R18 vs 255/35R18 (+2.25%)
- 235/35R18 vs 235/40R18 (+3.78%)
- 245/35R18 vs 255/35R18 (+1.11%)
- 245/35R18 vs 265/35R18 (+2.23%)
- 245/35R18 vs 245/40R18 (+3.90%)
- 215/40R18 vs 225/40R18 (+1.27%)
- 215/40R18 vs 235/40R18 (+2.54%)
- 215/40R18 vs 215/45R18 (+3.42%)
- 255/35R18 vs 265/35R18 (+1.10%)
- 255/35R18 vs 275/35R18 (+2.20%)
- 255/35R18 vs 255/40R18 (+4.01%)
- 225/40R18 vs 235/40R18 (+1.26%)
- 225/40R18 vs 245/40R18 (+2.51%)
- 225/40R18 vs 225/45R18 (+3.53%)
- 265/35R18 vs 275/35R18 (+1.09%)
- 265/35R18 vs 285/35R18 (+2.18%)
- 265/35R18 vs 265/40R18 (+4.12%)
- 235/40R18 vs 245/40R18 (+1.24%)
- 235/40R18 vs 255/40R18 (+2.48%)
- 235/40R18 vs 235/45R18 (+3.64%)
- 275/35R18 vs 285/35R18 (+1.08%)
Plus-size options from 18-inch
- 33x12.50R18 vs 33x12.50R20 (0.00%)
- 35x12.50R18 vs 35x12.50R20 (0.00%)
- 35x12.50R18 vs 35x13.50R20 (0.00%)
- 37x12.50R18 vs 37x12.50R20 (0.00%)
- 37x12.50R18 vs 37x13.50R20 (0.00%)
- 37x13.50R18 vs 37x12.50R20 (0.00%)
- 37x13.50R18 vs 37x13.50R20 (0.00%)
- 255/65R18 vs 255/60R19 (−0.01%)
- 255/60R18 vs 255/55R19 (−0.01%)
- 235/60R18 vs 285/45R19 (−0.01%)
- 255/55R18 vs 255/50R19 (−0.01%)
- 255/50R18 vs 255/45R19 (−0.01%)
- 255/45R18 vs 255/40R19 (−0.01%)
- 285/40R18 vs 225/45R19 (−0.01%)
- 225/50R18 vs 285/35R19 (−0.01%)
- 255/40R18 vs 255/35R19 (−0.02%)
- 225/45R18 vs 295/30R19 (−0.02%)
- 255/35R18 vs 255/30R19 (−0.02%)
- 315/70R18 vs 325/60R20 (−0.02%)
- 33x12.50R18 vs 275/60R20 (−0.02%)
Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.