Tire Size Box

305/50R17 vs 295/55R17

295/55R17 compared with 305/50R17

+2.6% diameter, −0.4" width

295/55R17 is 29.78" tall vs 29.01". Within the 3% rule, so usually interchangeable.

29.0"17" rim6.0"12.0" wide
305/50R17 (solid) compared with 295/55R17 (dashed outline), drawn to scale

With 295/55R17 tires, when your speedometer says 60 mph you are really going

61.6 mph

295/55R17 is +0.77 inches (+2.6%) in overall diameter. That is within the 3% most shops and makers allow.

305/50R17295/55R17Difference%
Overall diameter29.01"29.78"+0.77"+2.6%
Section width12.01"11.61"−0.39"−3.3%
Sidewall height6.00"6.39"+0.38"+6.4%
Circumference91.13"93.54"+2.41"+2.6%
Revolutions per mile695.3677.3−17.9−2.6%

Speedometer difference

If your vehicle came with 305/50R17 and you fit 295/55R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.5 mph+0.5 mph
30 mph30.8 mph+0.8 mph
40 mph41.1 mph+1.1 mph
50 mph51.3 mph+1.3 mph
60 mph61.6 mph+1.6 mph
65 mph66.7 mph+1.7 mph
70 mph71.9 mph+1.9 mph
75 mph77.0 mph+2.0 mph
80 mph82.1 mph+2.1 mph

Each size on its own

Questions

Which is bigger, 305/50R17 or 295/55R17?
295/55R17 is taller by 0.77 inches (29.78" vs 29.01"). 305/50R17 is wider by 0.39 inches.
Can I replace 305/50R17 with 295/55R17?
Usually, yes. The diameter difference is +2.6%, inside the 3% rule of thumb most tire shops use. Check that the wider or taller tire clears your suspension and fenders, and that its load index meets your placard.
How much will 295/55R17 change my speedometer?
When your speedometer reads 60 mph with 295/55R17 fitted (calibrated for 305/50R17), your real speed is 61.6 mph. Your odometer will under-count miles by about 2.6%.
Will 295/55R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.38 inches of ground clearance at the axle.

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