155/80R13 vs 195/50R15

195/50R15 is 0.09 in (2.2 mm) shorter than 155/80R13, a −0.38% diameter difference. With the speedometer set for 155/80R13, an indicated 60 mph is 59.8 mph on 195/50R15.

Is this a safe swap?

Diameter difference −0.38%: under 1%

By overall diameter alone, 195/50R15 is a near match for 155/80R13; 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.

155/80R13 vs 195/50R15 differences
Measurement	155/80R13	195/50R15	Difference	% diff
Overall diameter	22.76 in (578.2 mm)	22.68 in (576.0 mm)	−0.09 in (−2.2 mm)	−0.38%
Sidewall height	4.88 in (124.0 mm)	3.84 in (97.5 mm)	−1.04 in (−26.5 mm)	−21.37%
Section width	6.10 in (155.0 mm)	7.68 in (195.0 mm)	+1.57 in (+40.0 mm)	+25.81%
Circumference	71.51 in (1,816.5 mm)	71.24 in (1,809.6 mm)	−0.27 in (−6.9 mm)	−0.38%
Revolutions per mile	886	889	+3	+0.38%

True speed with the speedometer calibrated for 155/80R13
Indicated	Actual on 155/80R13	Actual on 195/50R15	Difference
30 mph	30.0 mph	29.9 mph	−0.1 mph
60 mph	60.0 mph	59.8 mph	−0.2 mph
75 mph	75.0 mph	74.7 mph	−0.3 mph

Ride-height change: 195/50R15 lowers the vehicle by 0.04 in (1.1 mm) at the axle (half the −2.2 mm diameter difference).

195/50R15 is 0.09 in shorter than 155/80R13 and 40 mm wider, a 0.38% difference in overall diameter.

With the speedometer calibrated for 155/80R13, an indicated 60 mph is actually 59.8 mph on 195/50R15, and revolutions per mile change from 886 to 889.

195/50R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 155/80R13.

Size pages

Other comparisons with 155/80R13

Other comparisons with 195/50R15

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