175/80R13 vs 225/50R15

225/50R15 is 0.17 in (4.2 mm) shorter than 175/80R13, a −0.69% diameter difference. With the speedometer set for 175/80R13, an indicated 60 mph is 59.6 mph on 225/50R15.

Is this a safe swap?

Diameter difference −0.69%: under 1%

By overall diameter alone, 225/50R15 is a near match for 175/80R13; the speedometer changes by less than 1%. 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.

175/80R13 vs 225/50R15 differences
Measurement	175/80R13	225/50R15	Difference	% diff
Overall diameter	24.02 in (610.2 mm)	23.86 in (606.0 mm)	−0.17 in (−4.2 mm)	−0.69%
Sidewall height	5.51 in (140.0 mm)	4.43 in (112.5 mm)	−1.08 in (−27.5 mm)	−19.64%
Section width	6.89 in (175.0 mm)	8.86 in (225.0 mm)	+1.97 in (+50.0 mm)	+28.57%
Circumference	75.47 in (1,917.0 mm)	74.95 in (1,903.8 mm)	−0.52 in (−13.2 mm)	−0.69%
Revolutions per mile	840	845	+6	+0.69%

True speed with the speedometer calibrated for 175/80R13
Indicated	Actual on 175/80R13	Actual on 225/50R15	Difference
30 mph	30.0 mph	29.8 mph	−0.2 mph
60 mph	60.0 mph	59.6 mph	−0.4 mph
75 mph	75.0 mph	74.5 mph	−0.5 mph

Ride-height change: 225/50R15 lowers the vehicle by 0.08 in (2.1 mm) at the axle (half the −4.2 mm diameter difference).

225/50R15 is 0.17 in shorter than 175/80R13 and 50 mm wider, a 0.69% difference in overall diameter.

With the speedometer calibrated for 175/80R13, an indicated 60 mph is actually 59.6 mph on 225/50R15, and revolutions per mile change from 840 to 845.

225/50R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 175/80R13.

Size pages

Other comparisons with 175/80R13

Other comparisons with 225/50R15

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