Tire Size Box

295/45R20 vs 295/50R20

295/50R20 compared with 295/45R20

+3.8% diameter, 0.0" width

295/50R20 is 31.61" tall vs 30.45". More than the 3% rule of thumb, so check carefully before switching.

30.5"20" rim5.2"11.6" wide
295/45R20 (solid) compared with 295/50R20 (dashed outline), drawn to scale

With 295/50R20 tires, when your speedometer says 60 mph you are really going

62.3 mph

295/50R20 is +1.16 inches (+3.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/45R20295/50R20Difference%
Overall diameter30.45"31.61"+1.16"+3.8%
Section width11.61"11.61"0.00"0.0%
Sidewall height5.23"5.81"+0.58"+11.1%
Circumference95.67"99.32"+3.65"+3.8%
Revolutions per mile662.3637.9−24.3−3.7%

Speedometer difference

If your vehicle came with 295/45R20 and you fit 295/50R20, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.1 mph+1.1 mph
40 mph41.5 mph+1.5 mph
50 mph51.9 mph+1.9 mph
60 mph62.3 mph+2.3 mph
65 mph67.5 mph+2.5 mph
70 mph72.7 mph+2.7 mph
75 mph77.9 mph+2.9 mph
80 mph83.1 mph+3.1 mph

Each size on its own

Questions

Which is bigger, 295/45R20 or 295/50R20?
295/50R20 is taller by 1.16 inches (31.61" vs 30.45"). 295/45R20 is the same width.
Can I replace 295/45R20 with 295/50R20?
It is not recommended without checking carefully. The diameter difference is +3.8%, 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 295/50R20 change my speedometer?
When your speedometer reads 60 mph with 295/50R20 fitted (calibrated for 295/45R20), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.8%.
Will 295/50R20 lift my vehicle?
Ride height changes by half the diameter difference: +0.58 inches of ground clearance at the axle.

Other comparisons