170Best 305/25 R21 tires
1 rated tire available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Pirelli P Zero at 70/100.
27″
overall diameter
12″
section width
21″
rim diameter
746.9
revs per mile
Best 305/25 R21 summer tires
1170Conversion
305/25 R21 in inches
| Overall diameter | 27″ |
| Section width | 12″ |
| Rim diameter | 21″ |
| Sidewall height | 76 mm |
| Circumference | 84.8″ |
| Revolutions per mile | 746.9 |
Wheels
What rims fit 305/25 R21 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
8.5″
Ideal
9.5″
Maximum
11″
Rim diameter is fixed at 21″ — only the width varies. Estimated from the 12″ section width (70–90% rule).
Fitted from the factory on rims: 21x10.5, 21x11, 21x11.5, 21x12.
Popular comparisons
Sizes often compared with 305/25 R21
Close alternatives — each opens in the tire size calculator.
Sidewall
305/25 R21 — what does it mean?
| Parameter | Meaning |
|---|---|
| 305 | The first number is the section width — 305 mm, or about 12 inches across the widest part of the tire. |
| 25 | The second number is the aspect ratio: sidewall height as a percentage of width. At 25%, the sidewall is about 76 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. |