Tire Size Box

245/70R15 vs 265/70R15

265/70R15 compared with 245/70R15

+3.9% diameter, +0.8" width

265/70R15 is 29.61" tall vs 28.50". More than the 3% rule of thumb, so check carefully before switching.

28.5"15" rim6.8"9.6" wide
245/70R15 (solid) compared with 265/70R15 (dashed outline), drawn to scale

With 265/70R15 tires, when your speedometer says 60 mph you are really going

62.3 mph

265/70R15 is +1.10 inches (+3.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/70R15265/70R15Difference%
Overall diameter28.50"29.61"+1.10"+3.9%
Section width9.65"10.43"+0.79"+8.2%
Sidewall height6.75"7.30"+0.55"+8.2%
Circumference89.55"93.01"+3.46"+3.9%
Revolutions per mile707.6681.2−26.3−3.7%

Speedometer difference

If your vehicle came with 245/70R15 and you fit 265/70R15, 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 mph41.5 mph+1.5 mph
50 mph51.9 mph+1.9 mph
60 mph62.3 mph+2.3 mph
65 mph67.5 mph+2.5 mph
70 mph72.7 mph+2.7 mph
75 mph77.9 mph+2.9 mph
80 mph83.1 mph+3.1 mph

Each size on its own

Questions

Which is bigger, 245/70R15 or 265/70R15?
265/70R15 is taller by 1.10 inches (29.61" vs 28.50"). 265/70R15 is wider by 0.79 inches.
Can I replace 245/70R15 with 265/70R15?
It is not recommended without checking carefully. The diameter difference is +3.9%, 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 265/70R15 change my speedometer?
When your speedometer reads 60 mph with 265/70R15 fitted (calibrated for 245/70R15), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.9%.
Will 265/70R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.55 inches of ground clearance at the axle.

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