205/75R15 vs 225/55R17

225/55R17 is 0.36 in (9.2 mm) shorter than 205/75R15, a −1.34% diameter difference. With the speedometer set for 205/75R15, an indicated 60 mph is 59.2 mph on 225/55R17.

Is this a safe swap?

Diameter difference −1.34%: within the ±3% guideline

By overall diameter alone, 225/55R17 falls inside the ±3% range commonly used as a guideline when replacing 205/75R15. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

205/75R15 vs 225/55R17 differences
Measurement	205/75R15	225/55R17	Difference	% diff
Overall diameter	27.11 in (688.5 mm)	26.74 in (679.3 mm)	−0.36 in (−9.2 mm)	−1.34%
Sidewall height	6.05 in (153.8 mm)	4.87 in (123.8 mm)	−1.18 in (−30.0 mm)	−19.51%
Section width	8.07 in (205.0 mm)	8.86 in (225.0 mm)	+0.79 in (+20.0 mm)	+9.76%
Circumference	85.16 in (2,163.0 mm)	84.02 in (2,134.1 mm)	−1.14 in (−28.9 mm)	−1.34%
Revolutions per mile	744	754	+10	+1.35%

True speed with the speedometer calibrated for 205/75R15
Indicated	Actual on 205/75R15	Actual on 225/55R17	Difference
30 mph	30.0 mph	29.6 mph	−0.4 mph
60 mph	60.0 mph	59.2 mph	−0.8 mph
75 mph	75.0 mph	74.0 mph	−1.0 mph

Ride-height change: 225/55R17 lowers the vehicle by 0.18 in (4.6 mm) at the axle (half the −9.2 mm diameter difference).

225/55R17 is 0.36 in shorter than 205/75R15 and 20 mm wider, a 1.34% difference in overall diameter.

With the speedometer calibrated for 205/75R15, an indicated 60 mph is actually 59.2 mph on 225/55R17, and revolutions per mile change from 744 to 754.

225/55R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 205/75R15.

Size pages

Other comparisons with 205/75R15

Other comparisons with 225/55R17

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.