Tire Size Box

295/50R20 vs 295/55R20

295/55R20 compared with 295/50R20

+3.7% diameter, 0.0" width

295/55R20 is 32.78" tall vs 31.61". More than the 3% rule of thumb, so check carefully before switching.

31.6"20" rim5.8"11.6" wide
295/50R20 (solid) compared with 295/55R20 (dashed outline), drawn to scale

With 295/55R20 tires, when your speedometer says 60 mph you are really going

62.2 mph

295/55R20 is +1.16 inches (+3.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/50R20295/55R20Difference%
Overall diameter31.61"32.78"+1.16"+3.7%
Section width11.61"11.61"0.00"0.0%
Sidewall height5.81"6.39"+0.58"+10.0%
Circumference99.32"102.97"+3.65"+3.7%
Revolutions per mile637.9615.3−22.6−3.5%

Speedometer difference

If your vehicle came with 295/50R20 and you fit 295/55R20, 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, 295/50R20 or 295/55R20?
295/55R20 is taller by 1.16 inches (32.78" vs 31.61"). 295/50R20 is the same width.
Can I replace 295/50R20 with 295/55R20?
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 295/55R20 change my speedometer?
When your speedometer reads 60 mph with 295/55R20 fitted (calibrated for 295/50R20), your real speed is 62.2 mph. Your odometer will under-count miles by about 3.7%.
Will 295/55R20 lift my vehicle?
Ride height changes by half the diameter difference: +0.58 inches of ground clearance at the axle.

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