Tire Size Box

255/50R16 vs 275/50R16

275/50R16 compared with 255/50R16

+3.0% diameter, +0.8" width

275/50R16 is 26.83" tall vs 26.04". More than the 3% rule of thumb, so check carefully before switching.

26.0"16" rim5.0"10.0" wide
255/50R16 (solid) compared with 275/50R16 (dashed outline), drawn to scale

With 275/50R16 tires, when your speedometer says 60 mph you are really going

61.8 mph

275/50R16 is +0.79 inches (+3.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

255/50R16275/50R16Difference%
Overall diameter26.04"26.83"+0.79"+3.0%
Section width10.04"10.83"+0.79"+7.8%
Sidewall height5.02"5.41"+0.39"+7.8%
Circumference81.81"84.28"+2.47"+3.0%
Revolutions per mile774.5751.8−22.7−2.9%

Speedometer difference

If your vehicle came with 255/50R16 and you fit 275/50R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph30.9 mph+0.9 mph
40 mph41.2 mph+1.2 mph
50 mph51.5 mph+1.5 mph
60 mph61.8 mph+1.8 mph
65 mph67.0 mph+2.0 mph
70 mph72.1 mph+2.1 mph
75 mph77.3 mph+2.3 mph
80 mph82.4 mph+2.4 mph

Each size on its own

Questions

Which is bigger, 255/50R16 or 275/50R16?
275/50R16 is taller by 0.79 inches (26.83" vs 26.04"). 275/50R16 is wider by 0.79 inches.
Can I replace 255/50R16 with 275/50R16?
It is not recommended without checking carefully. The diameter difference is +3.0%, 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 275/50R16 change my speedometer?
When your speedometer reads 60 mph with 275/50R16 fitted (calibrated for 255/50R16), your real speed is 61.8 mph. Your odometer will under-count miles by about 3.0%.
Will 275/50R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.39 inches of ground clearance at the axle.

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