Best 305/40R18 tires

1 rated tire available in this size, scored on dry, wet, snow, comfort and wear.

Top pick in 305/40R18

Nitto NT555RII

24 owner reviews

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Every rated 305/40R18 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 305/40R18 summer tires

1
  1. Nitto NT555RII

    24 owner reviews

    45 Check price on Amazon · 305/40R18

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Nearest sizes with rated tires

Within 3% of the overall diameter, on the same rim first. Check the sizes approved for your vehicle before you switch.

305/40R18 in inches

Overall diameter27.6″
Section width12″
Rim diameter18″
Sidewall height122 mm
Circumference86.7″
Revolutions per mile730.6

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

The closest flotation size is 28x12.00R18 — 1.4% taller and 0.1% narrower. Compare them in the calculator.

Compare 305/40R18 with another size in the tire size calculator

What rims fit 305/40R18 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″

The rim diameter is fixed at 18″; only the width can change. Rims are usually 70–90% as wide as the tire’s 12″ section width.

305/40R18 — what does it mean?

ParameterMeaning
305The first number is the section width — 305 mm, or about 12 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 122 mm tall.
R18R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 18-inch wheel.