Tire Size Box

225/55R18 vs 225/60R18

225/60R18 compared with 225/55R18

+3.2% diameter, 0.0" width

225/60R18 is 28.63" tall vs 27.74". More than the 3% rule of thumb, so check carefully before switching.

27.7"18" rim4.9"8.9" wide
225/55R18 (solid) compared with 225/60R18 (dashed outline), drawn to scale

With 225/60R18 tires, when your speedometer says 60 mph you are really going

61.9 mph

225/60R18 is +0.89 inches (+3.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/55R18225/60R18Difference%
Overall diameter27.74"28.63"+0.89"+3.2%
Section width8.86"8.86"0.00"0.0%
Sidewall height4.87"5.31"+0.44"+9.1%
Circumference87.16"89.94"+2.78"+3.2%
Revolutions per mile726.9704.4−22.5−3.1%

Speedometer difference

If your vehicle came with 225/55R18 and you fit 225/60R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.6 mph+1.6 mph
60 mph61.9 mph+1.9 mph
65 mph67.1 mph+2.1 mph
70 mph72.2 mph+2.2 mph
75 mph77.4 mph+2.4 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 225/55R18 or 225/60R18?
225/60R18 is taller by 0.89 inches (28.63" vs 27.74"). 225/55R18 is the same width.
Can I replace 225/55R18 with 225/60R18?
It is not recommended without checking carefully. The diameter difference is +3.2%, 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 225/60R18 change my speedometer?
When your speedometer reads 60 mph with 225/60R18 fitted (calibrated for 225/55R18), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.2%.
Will 225/60R18 lift my vehicle?
Ride height changes by half the diameter difference: +0.44 inches of ground clearance at the axle.

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