Tire Size Box

225/70R13 vs 245/70R13

245/70R13 compared with 225/70R13

+4.3% diameter, +0.8" width

245/70R13 is 26.50" tall vs 25.40". More than the 3% rule of thumb, so check carefully before switching.

25.4"13" rim6.2"8.9" wide
225/70R13 (solid) compared with 245/70R13 (dashed outline), drawn to scale

With 245/70R13 tires, when your speedometer says 60 mph you are really going

62.6 mph

245/70R13 is +1.10 inches (+4.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/70R13245/70R13Difference%
Overall diameter25.40"26.50"+1.10"+4.3%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height6.20"6.75"+0.55"+8.9%
Circumference79.80"83.26"+3.46"+4.3%
Revolutions per mile794.0760.9−33.0−4.2%

Speedometer difference

If your vehicle came with 225/70R13 and you fit 245/70R13, 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 mph73.0 mph+3.0 mph
75 mph78.3 mph+3.3 mph
80 mph83.5 mph+3.5 mph

Each size on its own

Questions

Which is bigger, 225/70R13 or 245/70R13?
245/70R13 is taller by 1.10 inches (26.50" vs 25.40"). 245/70R13 is wider by 0.79 inches.
Can I replace 225/70R13 with 245/70R13?
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 245/70R13 change my speedometer?
When your speedometer reads 60 mph with 245/70R13 fitted (calibrated for 225/70R13), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.3%.
Will 245/70R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.55 inches of ground clearance at the axle.

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