188Best 305/40 R23 tires
2 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the General Grabber UHP at 88/100.
32.6″
overall diameter
12″
section width
23″
rim diameter
618.5
revs per mile
Best 305/40 R23 summer tires
1188More top-rated 305/40 R23 tires
1
183Conversion
305/40 R23 in inches
| Overall diameter | 32.6″ |
| Section width | 12″ |
| Rim diameter | 23″ |
| Sidewall height | 122 mm |
| Circumference | 102.4″ |
| Revolutions per mile | 618.5 |
Wheels
What rims fit 305/40 R23 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 23″ — only the width varies. Estimated from the 12″ section width (70–90% rule).
Popular comparisons
Sizes often compared with 305/40 R23
Close alternatives — each opens in the tire size calculator.
Sidewall
305/40 R23 — 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. |
| 40 | The second number is the aspect ratio: sidewall height as a percentage of width. At 40%, the sidewall is about 122 mm tall. |
| R23 | R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 23-inch wheel. |