Tire Size Box

225/85R16 vs 245/85R16

245/85R16 compared with 225/85R16

+4.3% diameter, +0.8" width

245/85R16 is 32.40" tall vs 31.06". More than the 3% rule of thumb, so check carefully before switching.

31.1"16" rim7.5"8.9" wide
225/85R16 (solid) compared with 245/85R16 (dashed outline), drawn to scale

With 245/85R16 tires, when your speedometer says 60 mph you are really going

62.6 mph

245/85R16 is +1.34 inches (+4.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/85R16245/85R16Difference%
Overall diameter31.06"32.40"+1.34"+4.3%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height7.53"8.20"+0.67"+8.9%
Circumference97.57"101.78"+4.21"+4.3%
Revolutions per mile649.3622.5−26.8−4.1%

Speedometer difference

If your vehicle came with 225/85R16 and you fit 245/85R16, 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 mph78.2 mph+3.2 mph
80 mph83.4 mph+3.4 mph

Each size on its own

Questions

Which is bigger, 225/85R16 or 245/85R16?
245/85R16 is taller by 1.34 inches (32.40" vs 31.06"). 245/85R16 is wider by 0.79 inches.
Can I replace 225/85R16 with 245/85R16?
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 245/85R16 change my speedometer?
When your speedometer reads 60 mph with 245/85R16 fitted (calibrated for 225/85R16), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.3%.
Will 245/85R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.67 inches of ground clearance at the axle.

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