Tire Size Box

205/75R15 vs 225/75R15

225/75R15 compared with 205/75R15

+4.4% diameter, +0.8" width

225/75R15 is 28.29" tall vs 27.11". More than the 3% rule of thumb, so check carefully before switching.

27.1"15" rim6.1"8.1" wide
205/75R15 (solid) compared with 225/75R15 (dashed outline), drawn to scale

With 225/75R15 tires, when your speedometer says 60 mph you are really going

62.6 mph

225/75R15 is +1.18 inches (+4.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/75R15225/75R15Difference%
Overall diameter27.11"28.29"+1.18"+4.4%
Section width8.07"8.86"+0.79"+9.8%
Sidewall height6.05"6.64"+0.59"+9.8%
Circumference85.16"88.87"+3.71"+4.4%
Revolutions per mile744.0713.0−31.1−4.2%

Speedometer difference

If your vehicle came with 205/75R15 and you fit 225/75R15, 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 mph52.2 mph+2.2 mph
60 mph62.6 mph+2.6 mph
65 mph67.8 mph+2.8 mph
70 mph73.1 mph+3.1 mph
75 mph78.3 mph+3.3 mph
80 mph83.5 mph+3.5 mph

Each size on its own

Questions

Which is bigger, 205/75R15 or 225/75R15?
225/75R15 is taller by 1.18 inches (28.29" vs 27.11"). 225/75R15 is wider by 0.79 inches.
Can I replace 205/75R15 with 225/75R15?
It is not recommended without checking carefully. The diameter difference is +4.4%, 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 225/75R15 change my speedometer?
When your speedometer reads 60 mph with 225/75R15 fitted (calibrated for 205/75R15), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.4%.
Will 225/75R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.59 inches of ground clearance at the axle.

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