Tire Size Box

205/50R18 vs 205/60R18

205/60R18 compared with 205/50R18

+6.2% diameter, 0.0" width

205/60R18 is 27.69" tall vs 26.07". More than the 3% rule of thumb, so check carefully before switching.

26.1"18" rim4.0"8.1" wide
205/50R18 (solid) compared with 205/60R18 (dashed outline), drawn to scale

With 205/60R18 tires, when your speedometer says 60 mph you are really going

63.7 mph

205/60R18 is +1.61 inches (+6.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/50R18205/60R18Difference%
Overall diameter26.07"27.69"+1.61"+6.2%
Section width8.07"8.07"0.00"0.0%
Sidewall height4.04"4.84"+0.81"+20.0%
Circumference81.90"86.98"+5.07"+6.2%
Revolutions per mile773.6728.5−45.1−5.8%

Speedometer difference

If your vehicle came with 205/50R18 and you fit 205/60R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.2 mph+1.2 mph
30 mph31.9 mph+1.9 mph
40 mph42.5 mph+2.5 mph
50 mph53.1 mph+3.1 mph
60 mph63.7 mph+3.7 mph
65 mph69.0 mph+4.0 mph
70 mph74.3 mph+4.3 mph
75 mph79.6 mph+4.6 mph
80 mph85.0 mph+5.0 mph

Each size on its own

Questions

Which is bigger, 205/50R18 or 205/60R18?
205/60R18 is taller by 1.61 inches (27.69" vs 26.07"). 205/50R18 is the same width.
Can I replace 205/50R18 with 205/60R18?
It is not recommended without checking carefully. The diameter difference is +6.2%, 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 205/60R18 change my speedometer?
When your speedometer reads 60 mph with 205/60R18 fitted (calibrated for 205/50R18), your real speed is 63.7 mph. Your odometer will under-count miles by about 6.2%.
Will 205/60R18 lift my vehicle?
Ride height changes by half the diameter difference: +0.81 inches of ground clearance at the axle.

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