Best 235/40R21 tires

3 rated tires available in this size, scored on dry, wet, snow, comfort and wear.

Top pick in 235/40R21

Goodyear Eagle F1 Asymmetric 6

1,852 owner reviews · 31 tests

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Compare two 235/40R21 tires side by side

Every rated 235/40R21 tire, by season

Ranked by our Relative score, weighed against how many reviews and tests stand behind it.

How scores work
Relative score
0–100. Blends road tests (60%) and owner reviews (40%) category by category, the same way on every TireWheelGuide page. With only one of the two, the missing half is estimated from it, so the score stays closer to average. It needs at least one road test or five owner reviews.
Ranking
The score already allows for how much stands behind it: with only a few reviews or tests a tire stays near the typical score. Among similar scores, newer tires rank higher and tires replaced by a newer generation lower.

Best 235/40R21 summer tires

2
  1. Goodyear Eagle F1 Asymmetric 6

    1,852 owner reviews · 31 tests

    87 Check price on Amazon · 235/40R21
  2. Accelera Iota ST68

    1,616 owner reviews

    64 Check price on Amazon · 235/40R21

Best 235/40R21 winter tires

1
  1. Goodyear Ultra Grip Performance 3

    13 owner reviews · 27 tests

    82 Check price on Amazon · 235/40R21

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235/40R21 in inches

Overall diameter28.4″
Section width9.3″
Rim diameter21″
Sidewall height94 mm
Circumference89.2″
Revolutions per mile710.1

Revolutions per mile: how many times the tire turns in one mile, the count your speedometer is calibrated to.

Compare 235/40R21 with another size in the tire size calculator

What rims fit 235/40R21 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″

The rim diameter is fixed at 21″; only the width can change. Rims are usually 70–90% as wide as the tire’s 9.3″ section width.

235/40R21 — what does it mean?

ParameterMeaning
235The first number is the section width — 235 mm, or about 9.3 inches across the widest part of the tire.
40The second number is the aspect ratio: sidewall height as a percentage of width. At 40%, the sidewall is about 94 mm tall.
R21R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 21-inch wheel.