Tire Size Box

285/45R16 vs 285/55R16

285/55R16 compared with 285/45R16

+8.6% diameter, 0.0" width

285/55R16 is 28.34" tall vs 26.10". More than the 3% rule of thumb, so check carefully before switching.

26.1"16" rim5.0"11.2" wide
285/45R16 (solid) compared with 285/55R16 (dashed outline), drawn to scale

With 285/55R16 tires, when your speedometer says 60 mph you are really going

65.2 mph

285/55R16 is +2.24 inches (+8.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/45R16285/55R16Difference%
Overall diameter26.10"28.34"+2.24"+8.6%
Section width11.22"11.22"0.00"0.0%
Sidewall height5.05"6.17"+1.12"+22.2%
Circumference81.99"89.04"+7.05"+8.6%
Revolutions per mile772.8711.6−61.2−7.9%

Speedometer difference

If your vehicle came with 285/45R16 and you fit 285/55R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.7 mph+1.7 mph
30 mph32.6 mph+2.6 mph
40 mph43.4 mph+3.4 mph
50 mph54.3 mph+4.3 mph
60 mph65.2 mph+5.2 mph
65 mph70.6 mph+5.6 mph
70 mph76.0 mph+6.0 mph
75 mph81.4 mph+6.4 mph
80 mph86.9 mph+6.9 mph

Each size on its own

Questions

Which is bigger, 285/45R16 or 285/55R16?
285/55R16 is taller by 2.24 inches (28.34" vs 26.10"). 285/45R16 is the same width.
Can I replace 285/45R16 with 285/55R16?
It is not recommended without checking carefully. The diameter difference is +8.6%, 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 285/55R16 change my speedometer?
When your speedometer reads 60 mph with 285/55R16 fitted (calibrated for 285/45R16), your real speed is 65.2 mph. Your odometer will under-count miles by about 8.6%.
Will 285/55R16 lift my vehicle?
Ride height changes by half the diameter difference: +1.12 inches of ground clearance at the axle.

Other comparisons