Tire Size Box

225/85R14 vs 245/85R14

245/85R14 compared with 225/85R14

+4.6% diameter, +0.8" width

245/85R14 is 30.40" tall vs 29.06". More than the 3% rule of thumb, so check carefully before switching.

29.1"14" rim7.5"8.9" wide
225/85R14 (solid) compared with 245/85R14 (dashed outline), drawn to scale

With 245/85R14 tires, when your speedometer says 60 mph you are really going

62.8 mph

245/85R14 is +1.34 inches (+4.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/85R14245/85R14Difference%
Overall diameter29.06"30.40"+1.34"+4.6%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height7.53"8.20"+0.67"+8.9%
Circumference91.29"95.50"+4.21"+4.6%
Revolutions per mile694.0663.5−30.6−4.4%

Speedometer difference

If your vehicle came with 225/85R14 and you fit 245/85R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.4 mph+1.4 mph
40 mph41.8 mph+1.8 mph
50 mph52.3 mph+2.3 mph
60 mph62.8 mph+2.8 mph
65 mph68.0 mph+3.0 mph
70 mph73.2 mph+3.2 mph
75 mph78.5 mph+3.5 mph
80 mph83.7 mph+3.7 mph

Each size on its own

Questions

Which is bigger, 225/85R14 or 245/85R14?
245/85R14 is taller by 1.34 inches (30.40" vs 29.06"). 245/85R14 is wider by 0.79 inches.
Can I replace 225/85R14 with 245/85R14?
It is not recommended without checking carefully. The diameter difference is +4.6%, 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 245/85R14 change my speedometer?
When your speedometer reads 60 mph with 245/85R14 fitted (calibrated for 225/85R14), your real speed is 62.8 mph. Your odometer will under-count miles by about 4.6%.
Will 245/85R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.67 inches of ground clearance at the axle.

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