Tire Size Box

205/45R16 vs 205/50R16

205/50R16 compared with 205/45R16

+3.5% diameter, 0.0" width

205/50R16 is 24.07" tall vs 23.26". More than the 3% rule of thumb, so check carefully before switching.

23.3"16" rim3.6"8.1" wide
205/45R16 (solid) compared with 205/50R16 (dashed outline), drawn to scale

With 205/50R16 tires, when your speedometer says 60 mph you are really going

62.1 mph

205/50R16 is +0.81 inches (+3.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/45R16205/50R16Difference%
Overall diameter23.26"24.07"+0.81"+3.5%
Section width8.07"8.07"0.00"0.0%
Sidewall height3.63"4.04"+0.40"+11.1%
Circumference73.09"75.62"+2.54"+3.5%
Revolutions per mile866.9837.9−29.1−3.4%

Speedometer difference

If your vehicle came with 205/45R16 and you fit 205/50R16, 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 mph41.4 mph+1.4 mph
50 mph51.7 mph+1.7 mph
60 mph62.1 mph+2.1 mph
65 mph67.3 mph+2.3 mph
70 mph72.4 mph+2.4 mph
75 mph77.6 mph+2.6 mph
80 mph82.8 mph+2.8 mph

Each size on its own

Questions

Which is bigger, 205/45R16 or 205/50R16?
205/50R16 is taller by 0.81 inches (24.07" vs 23.26"). 205/45R16 is the same width.
Can I replace 205/45R16 with 205/50R16?
It is not recommended without checking carefully. The diameter difference is +3.5%, 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 205/50R16 change my speedometer?
When your speedometer reads 60 mph with 205/50R16 fitted (calibrated for 205/45R16), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.5%.
Will 205/50R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.40 inches of ground clearance at the axle.

Other comparisons