175/70R13 vs 205/50R15

205/50R15 is 0.43 in (10.8 mm) taller than 175/70R13, a +1.88% diameter difference. With the speedometer set for 175/70R13, an indicated 60 mph is 61.1 mph on 205/50R15.

Is this a safe swap?

Diameter difference +1.88%: within the ±3% guideline

By overall diameter alone, 205/50R15 falls inside the ±3% range commonly used as a guideline when replacing 175/70R13. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 175/70R13 (22.65 in) vs 205/50R15 (23.07 in)175/70R1322.65 in × 6.89 in205/50R1523.07 in × 8.07 in
Side profile and tread width, drawn to the same scale.
175/70R13 vs 205/50R15 differences
Measurement175/70R13205/50R15Difference% diff
Overall diameter22.65 in (575.2 mm)23.07 in (586.0 mm)+0.43 in (+10.8 mm)+1.88%
Sidewall height4.82 in (122.5 mm)4.04 in (102.5 mm)−0.79 in (−20.0 mm)−16.33%
Section width6.89 in (175.0 mm)8.07 in (205.0 mm)+1.18 in (+30.0 mm)+17.14%
Circumference71.14 in (1,807.0 mm)72.48 in (1,841.0 mm)+1.34 in (+33.9 mm)+1.88%
Revolutions per mile891874−16−1.84%
True speed with the speedometer calibrated for 175/70R13
IndicatedActual on 175/70R13Actual on 205/50R15Difference
30 mph30.0 mph30.6 mph+0.6 mph
60 mph60.0 mph61.1 mph+1.1 mph
75 mph75.0 mph76.4 mph+1.4 mph

Ride-height change: 205/50R15 raises the vehicle by 0.21 in (5.4 mm) at the axle (half the +10.8 mm diameter difference).

205/50R15 is 0.43 in taller than 175/70R13 and 30 mm wider, a 1.88% difference in overall diameter.

With the speedometer calibrated for 175/70R13, an indicated 60 mph is actually 61.1 mph on 205/50R15, and revolutions per mile change from 891 to 874.

205/50R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 175/70R13.

Size pages

Other comparisons with 175/70R13

Other comparisons with 205/50R15

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.