TireSize

265/70R18 Tire Size

265/70R18 diameter, sidewall, revolutions per mile, and plus-sizing options.

The 265/70R18 tire size breaks down as: 265 mm section width, 70% aspect ratio, and a 18-inch rim. Below are its real, calculated dimensions.

265/70R18 Calculated Dimensions

MetricValue
Overall diameter32.6 in (828 mm)
Sidewall height7.3 in (186 mm)
Circumference102.4 in (2602 mm)
Revolutions per mile619

Typical Fitment

265/70R18 is most often found on SUVs and light trucks. Always confirm against the door-jamb placard or owner manual before fitting.

Plus-Sizing Alternatives

These sizes keep the overall diameter close to 265/70R18, so speedometer and gearing stay near stock:

SizeDiameterDiameter change
275/65R1832.07 in-1.6%
275/65R1933.07 in+1.4%
285/55R2032.34 in-0.8%

Speedometer Note

If you fit a 275/65R18 instead of 265/70R18, the diameter changes by -1.6%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 61 mph. A shorter tire has the opposite effect, so the gauge reads high.

Use the tire calculator to compare 265/70R18 against any other size and see the exact diameter and speedometer difference.

By Daniel Reyes, automotive editor

Frequently Asked Questions

What does 265/70R18 mean?

265/70R18 means a 265 mm wide tire with a 70% sidewall aspect ratio mounted on a 18-inch rim. The aspect ratio is the sidewall height as a percentage of the width.

Can I plus-size from 265/70R18?

Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 265/70R18 are 275/65R18, 275/65R19, 285/55R20.

Will 265/70R18 affect my speedometer?

Only if it differs in diameter from your original size. A taller tire reads low; a shorter tire reads high. Compare the two sizes with the calculator to find the percentage.

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