179Best 255/45 R21 tires
4 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Nokian Hakkapeliitta R5 EV at 93/100.
30″
overall diameter
10″
section width
21″
rim diameter
671.5
revs per mile
Best 255/45 R21 summer tires
3179
276
375More top-rated 255/45 R21 tires
1
193Conversion
255/45 R21 in inches
| Overall diameter | 30″ |
| Section width | 10″ |
| Rim diameter | 21″ |
| Sidewall height | 115 mm |
| Circumference | 94.4″ |
| Revolutions per mile | 671.5 |
Wheels
What rims fit 255/45 R21 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
7″
Ideal
8″
Maximum
9″
Rim diameter is fixed at 21″ — only the width varies. Estimated from the 10″ section width (70–90% rule).
Fitted from the factory on rims: 21x8, 21x8.5, 21x9, 21x9.5.
Sidewall
255/45 R21 — what does it mean?
| Parameter | Meaning |
|---|---|
| 255 | The first number is the section width — 255 mm, or about 10 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 115 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. |