Tire Size Box

225/60R15 vs 245/60R15

245/60R15 compared with 225/60R15

+3.7% diameter, +0.8" width

245/60R15 is 26.57" tall vs 25.63". More than the 3% rule of thumb, so check carefully before switching.

25.6"15" rim5.3"8.9" wide
225/60R15 (solid) compared with 245/60R15 (dashed outline), drawn to scale

With 245/60R15 tires, when your speedometer says 60 mph you are really going

62.2 mph

245/60R15 is +0.94 inches (+3.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/60R15245/60R15Difference%
Overall diameter25.63"26.57"+0.94"+3.7%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height5.31"5.79"+0.47"+8.9%
Circumference80.52"83.49"+2.97"+3.7%
Revolutions per mile786.9758.9−28.0−3.6%

Speedometer difference

If your vehicle came with 225/60R15 and you fit 245/60R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.1 mph+1.1 mph
40 mph41.5 mph+1.5 mph
50 mph51.8 mph+1.8 mph
60 mph62.2 mph+2.2 mph
65 mph67.4 mph+2.4 mph
70 mph72.6 mph+2.6 mph
75 mph77.8 mph+2.8 mph
80 mph82.9 mph+2.9 mph

Each size on its own

Questions

Which is bigger, 225/60R15 or 245/60R15?
245/60R15 is taller by 0.94 inches (26.57" vs 25.63"). 245/60R15 is wider by 0.79 inches.
Can I replace 225/60R15 with 245/60R15?
It is not recommended without checking carefully. The diameter difference is +3.7%, 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 245/60R15 change my speedometer?
When your speedometer reads 60 mph with 245/60R15 fitted (calibrated for 225/60R15), your real speed is 62.2 mph. Your odometer will under-count miles by about 3.7%.
Will 245/60R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.47 inches of ground clearance at the axle.

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