Best 235/30 R18 tires
We don't have rated tires listed in this size yet — the conversion, rim fitment and comparisons below still apply.
23.6″
overall diameter
9.3″
section width
18″
rim diameter
856.4
revs per mile
Conversion
235/30 R18 in inches
| Overall diameter | 23.6″ |
| Section width | 9.3″ |
| Rim diameter | 18″ |
| Sidewall height | 71 mm |
| Circumference | 74″ |
| Revolutions per mile | 856.4 |
The closest flotation size is 28x12.00R18 — 18.9% taller and 29.7% wider. Compare them in the calculator.
Wheels
What rims fit 235/30 R18 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
6.5″
Ideal
7.5″
Maximum
8.5″
Rim diameter is fixed at 18″ — only the width varies. Estimated from the 9.3″ section width (70–90% rule).
Fitted from the factory on rims: 18x8.
Sidewall
235/30 R18 — what does it mean?
| Parameter | Meaning |
|---|---|
| 235 | The first number is the section width — 235 mm, or about 9.3 inches across the widest part of the tire. |
| 30 | The second number is the aspect ratio: sidewall height as a percentage of width. At 30%, the sidewall is about 71 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. |