Tire Size Box

225/55R14 vs 225/65R14

225/65R14 compared with 225/55R14

+7.5% diameter, 0.0" width

225/65R14 is 25.52" tall vs 23.74". More than the 3% rule of thumb, so check carefully before switching.

23.7"14" rim4.9"8.9" wide
225/55R14 (solid) compared with 225/65R14 (dashed outline), drawn to scale

With 225/65R14 tires, when your speedometer says 60 mph you are really going

64.5 mph

225/65R14 is +1.77 inches (+7.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/55R14225/65R14Difference%
Overall diameter23.74"25.52"+1.77"+7.5%
Section width8.86"8.86"0.00"0.0%
Sidewall height4.87"5.76"+0.89"+18.2%
Circumference74.59"80.16"+5.57"+7.5%
Revolutions per mile849.4790.4−59.0−6.9%

Speedometer difference

If your vehicle came with 225/55R14 and you fit 225/65R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.2 mph+2.2 mph
40 mph43.0 mph+3.0 mph
50 mph53.7 mph+3.7 mph
60 mph64.5 mph+4.5 mph
65 mph69.8 mph+4.8 mph
70 mph75.2 mph+5.2 mph
75 mph80.6 mph+5.6 mph
80 mph86.0 mph+6.0 mph

Each size on its own

Questions

Which is bigger, 225/55R14 or 225/65R14?
225/65R14 is taller by 1.77 inches (25.52" vs 23.74"). 225/55R14 is the same width.
Can I replace 225/55R14 with 225/65R14?
It is not recommended without checking carefully. The diameter difference is +7.5%, 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 225/65R14 change my speedometer?
When your speedometer reads 60 mph with 225/65R14 fitted (calibrated for 225/55R14), your real speed is 64.5 mph. Your odometer will under-count miles by about 7.5%.
Will 225/65R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.89 inches of ground clearance at the axle.

Other comparisons