184Best 235/45 R21 tires
3 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Michelin Pilot Sport 4 SUV at 84/100.
29.3″
overall diameter
9.3″
section width
21″
rim diameter
687.7
revs per mile
Best 235/45 R21 summer tires
2184
287More top-rated 235/45 R21 tires
1
158Conversion
235/45 R21 in inches
| Overall diameter | 29.3″ |
| Section width | 9.3″ |
| Rim diameter | 21″ |
| Sidewall height | 106 mm |
| Circumference | 92.1″ |
| Revolutions per mile | 687.7 |
Wheels
What rims fit 235/45 R21 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 21″ — only the width varies. Estimated from the 9.3″ section width (70–90% rule).
Fitted from the factory on rims: 21x8, 21x8.5, 21x9.
Popular comparisons
Sizes often compared with 235/45 R21
Close alternatives — each opens in the tire size calculator.
Sidewall
235/45 R21 — 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. |
| 45 | The second number is the aspect ratio: sidewall height as a percentage of width. At 45%, the sidewall is about 106 mm tall. |
| R21 | R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 21-inch wheel. |