Tire Size Box

245/55R15 vs 265/55R15

265/55R15 compared with 245/55R15

+3.4% diameter, +0.8" width

265/55R15 is 26.48" tall vs 25.61". More than the 3% rule of thumb, so check carefully before switching.

25.6"15" rim5.3"9.6" wide
245/55R15 (solid) compared with 265/55R15 (dashed outline), drawn to scale

With 265/55R15 tires, when your speedometer says 60 mph you are really going

62.0 mph

265/55R15 is +0.87 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/55R15265/55R15Difference%
Overall diameter25.61"26.48"+0.87"+3.4%
Section width9.65"10.43"+0.79"+8.2%
Sidewall height5.31"5.74"+0.43"+8.2%
Circumference80.46"83.18"+2.72"+3.4%
Revolutions per mile787.5761.7−25.8−3.3%

Speedometer difference

If your vehicle came with 245/55R15 and you fit 265/55R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.4 mph+1.4 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.2 mph+2.2 mph
70 mph72.4 mph+2.4 mph
75 mph77.5 mph+2.5 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 245/55R15 or 265/55R15?
265/55R15 is taller by 0.87 inches (26.48" vs 25.61"). 265/55R15 is wider by 0.79 inches.
Can I replace 245/55R15 with 265/55R15?
It is not recommended without checking carefully. The diameter difference is +3.4%, more than the 3% most shops and makers allow. It will throw off the speedometer and may affect ABS, stability control and clearance.
How much will 265/55R15 change my speedometer?
When your speedometer reads 60 mph with 265/55R15 fitted (calibrated for 245/55R15), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.4%.
Will 265/55R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.43 inches of ground clearance at the axle.

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