Tire Size Box

225/55R16 vs 245/55R16

245/55R16 compared with 225/55R16

+3.4% diameter, +0.8" width

245/55R16 is 26.61" tall vs 25.74". More than the 3% rule of thumb, so check carefully before switching.

25.7"16" rim4.9"8.9" wide
225/55R16 (solid) compared with 245/55R16 (dashed outline), drawn to scale

With 245/55R16 tires, when your speedometer says 60 mph you are really going

62.0 mph

245/55R16 is +0.87 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/55R16245/55R16Difference%
Overall diameter25.74"26.61"+0.87"+3.4%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height4.87"5.31"+0.43"+8.9%
Circumference80.88"83.60"+2.72"+3.4%
Revolutions per mile783.4757.9−25.5−3.3%

Speedometer difference

If your vehicle came with 225/55R16 and you fit 245/55R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.2 mph+2.2 mph
70 mph72.4 mph+2.4 mph
75 mph77.5 mph+2.5 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 225/55R16 or 245/55R16?
245/55R16 is taller by 0.87 inches (26.61" vs 25.74"). 245/55R16 is wider by 0.79 inches.
Can I replace 225/55R16 with 245/55R16?
It is not recommended without checking carefully. The diameter difference is +3.4%, 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 245/55R16 change my speedometer?
When your speedometer reads 60 mph with 245/55R16 fitted (calibrated for 225/55R16), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.4%.
Will 245/55R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.43 inches of ground clearance at the axle.

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