Tire Size Box

295/50R21 vs 295/55R21

295/55R21 compared with 295/50R21

+3.6% diameter, 0.0" width

295/55R21 is 33.78" tall vs 32.61". More than the 3% rule of thumb, so check carefully before switching.

32.6"21" rim5.8"11.6" wide
295/50R21 (solid) compared with 295/55R21 (dashed outline), drawn to scale

With 295/55R21 tires, when your speedometer says 60 mph you are really going

62.1 mph

295/55R21 is +1.16 inches (+3.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/50R21295/55R21Difference%
Overall diameter32.61"33.78"+1.16"+3.6%
Section width11.61"11.61"0.00"0.0%
Sidewall height5.81"6.39"+0.58"+10.0%
Circumference102.46"106.11"+3.65"+3.6%
Revolutions per mile618.4597.1−21.3−3.4%

Speedometer difference

If your vehicle came with 295/50R21 and you fit 295/55R21, 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 mph41.4 mph+1.4 mph
50 mph51.8 mph+1.8 mph
60 mph62.1 mph+2.1 mph
65 mph67.3 mph+2.3 mph
70 mph72.5 mph+2.5 mph
75 mph77.7 mph+2.7 mph
80 mph82.8 mph+2.8 mph

Each size on its own

Questions

Which is bigger, 295/50R21 or 295/55R21?
295/55R21 is taller by 1.16 inches (33.78" vs 32.61"). 295/50R21 is the same width.
Can I replace 295/50R21 with 295/55R21?
It is not recommended without checking carefully. The diameter difference is +3.6%, 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 295/55R21 change my speedometer?
When your speedometer reads 60 mph with 295/55R21 fitted (calibrated for 295/50R21), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.6%.
Will 295/55R21 lift my vehicle?
Ride height changes by half the diameter difference: +0.58 inches of ground clearance at the axle.

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