188Best 275/40 R21 tires
33 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Michelin Pilot Sport All Season 4 at 88/100.
29.7″
overall diameter
10.8″
section width
21″
rim diameter
679.9
revs per mile
More top-rated 275/40 R21 tires
11188
288
388
487
584
686
788
880
988
1092
1174Best 275/40 R21 summer tires
10
184
283
387
481
577
676
874
973
1072Best 275/40 R21 all-season tires
9
188
286
380
480
578
676
774
867
962Best 275/40 R21 winter tires
3
182
281
381Conversion
275/40 R21 in inches
| Overall diameter | 29.7″ |
| Section width | 10.8″ |
| Rim diameter | 21″ |
| Sidewall height | 110 mm |
| Circumference | 93.2″ |
| Revolutions per mile | 679.9 |
Wheels
What rims fit 275/40 R21 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
7.5″
Ideal
8.5″
Maximum
9.5″
Rim diameter is fixed at 21″ — only the width varies. Estimated from the 10.8″ section width (70–90% rule).
Fitted from the factory on rims: 21x9, 21x9.5, 21x10, 21x10.5, 21x11.
Popular comparisons
Sizes often compared with 275/40 R21
Close alternatives — each opens in the tire size calculator.
Sidewall
275/40 R21 — what does it mean?
| Parameter | Meaning |
|---|---|
| 275 | The first number is the section width — 275 mm, or about 10.8 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 110 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. |