189Best 215/40 R18 tires
37 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Michelin Pilot Sport 4 at 89/100.
24.8″
overall diameter
8.5″
section width
18″
rim diameter
814.2
revs per mile
Best 215/40 R18 summer tires
20189
289
384
482
582
682
789
879
979
1175
12758 more rated tires in this size are listed on their brand pages.
Best 215/40 R18 all-season tires
9
188
286
384
484
582
680
776
872
961More top-rated 215/40 R18 tires
7
184
283
383
479
592
672
Best 215/40 R18 winter tires
1
178Conversion
215/40 R18 in inches
| Overall diameter | 24.8″ |
| Section width | 8.5″ |
| Rim diameter | 18″ |
| Sidewall height | 86 mm |
| Circumference | 77.8″ |
| Revolutions per mile | 814.2 |
The closest flotation size is 28x12.00R18 — 13% taller and 41.8% wider. Compare them in the calculator.
Wheels
What rims fit 215/40 R18 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
6″
Ideal
7″
Maximum
7.5″
Rim diameter is fixed at 18″ — only the width varies. Estimated from the 8.5″ section width (70–90% rule).
Fitted from the factory on rims: 18x7, 18x7.5, 18x8, 18x8.5.
Popular comparisons
Sizes often compared with 215/40 R18
Close alternatives — each opens in the tire size calculator.
Sidewall
215/40 R18 — what does it mean?
| Parameter | Meaning |
|---|---|
| 215 | The first number is the section width — 215 mm, or about 8.5 inches across the widest part of the tire. |
| 40 | The second number is the aspect ratio: sidewall height as a percentage of width. At 40%, the sidewall is about 86 mm tall. |
| R18 | R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 18-inch wheel. |