Tire Size Box

265/45R15 vs 265/50R15

265/50R15 compared with 265/45R15

+4.3% diameter, 0.0" width

265/50R15 is 25.43" tall vs 24.39". More than the 3% rule of thumb, so check carefully before switching.

24.4"15" rim4.7"10.4" wide
265/45R15 (solid) compared with 265/50R15 (dashed outline), drawn to scale

With 265/50R15 tires, when your speedometer says 60 mph you are really going

62.6 mph

265/50R15 is +1.04 inches (+4.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/45R15265/50R15Difference%
Overall diameter24.39"25.43"+1.04"+4.3%
Section width10.43"10.43"0.00"0.0%
Sidewall height4.69"5.22"+0.52"+11.1%
Circumference76.62"79.90"+3.28"+4.3%
Revolutions per mile826.9793.0−33.9−4.1%

Speedometer difference

If your vehicle came with 265/45R15 and you fit 265/50R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.3 mph+1.3 mph
40 mph41.7 mph+1.7 mph
50 mph52.1 mph+2.1 mph
60 mph62.6 mph+2.6 mph
65 mph67.8 mph+2.8 mph
70 mph73.0 mph+3.0 mph
75 mph78.2 mph+3.2 mph
80 mph83.4 mph+3.4 mph

Each size on its own

Questions

Which is bigger, 265/45R15 or 265/50R15?
265/50R15 is taller by 1.04 inches (25.43" vs 24.39"). 265/45R15 is the same width.
Can I replace 265/45R15 with 265/50R15?
It is not recommended without checking carefully. The diameter difference is +4.3%, 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 265/50R15 change my speedometer?
When your speedometer reads 60 mph with 265/50R15 fitted (calibrated for 265/45R15), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.3%.
Will 265/50R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.52 inches of ground clearance at the axle.

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