Tire Size Box

245/75R15 vs 265/75R15

265/75R15 compared with 245/75R15

+4.0% diameter, +0.8" width

265/75R15 is 30.65" tall vs 29.47". More than the 3% rule of thumb, so check carefully before switching.

29.5"15" rim7.2"9.6" wide
245/75R15 (solid) compared with 265/75R15 (dashed outline), drawn to scale

With 265/75R15 tires, when your speedometer says 60 mph you are really going

62.4 mph

265/75R15 is +1.18 inches (+4.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/75R15265/75R15Difference%
Overall diameter29.47"30.65"+1.18"+4.0%
Section width9.65"10.43"+0.79"+8.2%
Sidewall height7.23"7.82"+0.59"+8.2%
Circumference92.58"96.29"+3.71"+4.0%
Revolutions per mile684.4658.0−26.4−3.9%

Speedometer difference

If your vehicle came with 245/75R15 and you fit 265/75R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.2 mph+1.2 mph
40 mph41.6 mph+1.6 mph
50 mph52.0 mph+2.0 mph
60 mph62.4 mph+2.4 mph
65 mph67.6 mph+2.6 mph
70 mph72.8 mph+2.8 mph
75 mph78.0 mph+3.0 mph
80 mph83.2 mph+3.2 mph

Each size on its own

Questions

Which is bigger, 245/75R15 or 265/75R15?
265/75R15 is taller by 1.18 inches (30.65" vs 29.47"). 265/75R15 is wider by 0.79 inches.
Can I replace 245/75R15 with 265/75R15?
It is not recommended without checking carefully. The diameter difference is +4.0%, 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 265/75R15 change my speedometer?
When your speedometer reads 60 mph with 265/75R15 fitted (calibrated for 245/75R15), your real speed is 62.4 mph. Your odometer will under-count miles by about 4.0%.
Will 265/75R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.59 inches of ground clearance at the axle.

Other comparisons