Tire Size Box

225/60R18 vs 225/65R18

225/65R18 compared with 225/60R18

+3.1% diameter, 0.0" width

225/65R18 is 29.52" tall vs 28.63". More than the 3% rule of thumb, so check carefully before switching.

28.6"18" rim5.3"8.9" wide
225/60R18 (solid) compared with 225/65R18 (dashed outline), drawn to scale

With 225/65R18 tires, when your speedometer says 60 mph you are really going

61.9 mph

225/65R18 is +0.89 inches (+3.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/60R18225/65R18Difference%
Overall diameter28.63"29.52"+0.89"+3.1%
Section width8.86"8.86"0.00"0.0%
Sidewall height5.31"5.76"+0.44"+8.3%
Circumference89.94"92.73"+2.78"+3.1%
Revolutions per mile704.4683.3−21.1−3.0%

Speedometer difference

If your vehicle came with 225/60R18 and you fit 225/65R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph30.9 mph+0.9 mph
40 mph41.2 mph+1.2 mph
50 mph51.5 mph+1.5 mph
60 mph61.9 mph+1.9 mph
65 mph67.0 mph+2.0 mph
70 mph72.2 mph+2.2 mph
75 mph77.3 mph+2.3 mph
80 mph82.5 mph+2.5 mph

Each size on its own

Questions

Which is bigger, 225/60R18 or 225/65R18?
225/65R18 is taller by 0.89 inches (29.52" vs 28.63"). 225/60R18 is the same width.
Can I replace 225/60R18 with 225/65R18?
It is not recommended without checking carefully. The diameter difference is +3.1%, 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 225/65R18 change my speedometer?
When your speedometer reads 60 mph with 225/65R18 fitted (calibrated for 225/60R18), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.1%.
Will 225/65R18 lift my vehicle?
Ride height changes by half the diameter difference: +0.44 inches of ground clearance at the axle.

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