Tire Size Box

225/75R13 vs 245/75R13

245/75R13 compared with 225/75R13

+4.5% diameter, +0.8" width

245/75R13 is 27.47" tall vs 26.29". More than the 3% rule of thumb, so check carefully before switching.

26.3"13" rim6.6"8.9" wide
225/75R13 (solid) compared with 245/75R13 (dashed outline), drawn to scale

With 245/75R13 tires, when your speedometer says 60 mph you are really going

62.7 mph

245/75R13 is +1.18 inches (+4.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/75R13245/75R13Difference%
Overall diameter26.29"27.47"+1.18"+4.5%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height6.64"7.23"+0.59"+8.9%
Circumference82.58"86.29"+3.71"+4.5%
Revolutions per mile767.2734.2−33.0−4.3%

Speedometer difference

If your vehicle came with 225/75R13 and you fit 245/75R13, 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 mph41.8 mph+1.8 mph
50 mph52.2 mph+2.2 mph
60 mph62.7 mph+2.7 mph
65 mph67.9 mph+2.9 mph
70 mph73.1 mph+3.1 mph
75 mph78.4 mph+3.4 mph
80 mph83.6 mph+3.6 mph

Each size on its own

Questions

Which is bigger, 225/75R13 or 245/75R13?
245/75R13 is taller by 1.18 inches (27.47" vs 26.29"). 245/75R13 is wider by 0.79 inches.
Can I replace 225/75R13 with 245/75R13?
It is not recommended without checking carefully. The diameter difference is +4.5%, 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 245/75R13 change my speedometer?
When your speedometer reads 60 mph with 245/75R13 fitted (calibrated for 225/75R13), your real speed is 62.7 mph. Your odometer will under-count miles by about 4.5%.
Will 245/75R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.59 inches of ground clearance at the axle.

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