185/70R13 vs 195/55R15

195/55R15 is 0.25 in (6.3 mm) taller than 185/70R13, a +1.07% diameter difference. With the speedometer set for 185/70R13, an indicated 60 mph is 60.6 mph on 195/55R15.

Is this a safe swap?

Diameter difference +1.07%: within the ±3% guideline

By overall diameter alone, 195/55R15 falls inside the ±3% range commonly used as a guideline when replacing 185/70R13. 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.

185/70R13 vs 195/55R15 differences
Measurement	185/70R13	195/55R15	Difference	% diff
Overall diameter	23.20 in (589.2 mm)	23.44 in (595.5 mm)	+0.25 in (+6.3 mm)	+1.07%
Sidewall height	5.10 in (129.5 mm)	4.22 in (107.3 mm)	−0.88 in (−22.2 mm)	−17.18%
Section width	7.28 in (185.0 mm)	7.68 in (195.0 mm)	+0.39 in (+10.0 mm)	+5.41%
Circumference	72.88 in (1,851.0 mm)	73.65 in (1,870.8 mm)	+0.78 in (+19.8 mm)	+1.07%
Revolutions per mile	869	860	−9	−1.06%

True speed with the speedometer calibrated for 185/70R13
Indicated	Actual on 185/70R13	Actual on 195/55R15	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.6 mph	+0.6 mph
75 mph	75.0 mph	75.8 mph	+0.8 mph

Ride-height change: 195/55R15 raises the vehicle by 0.12 in (3.1 mm) at the axle (half the +6.3 mm diameter difference).

195/55R15 is 0.25 in taller than 185/70R13 and 10 mm wider, a 1.07% difference in overall diameter.

With the speedometer calibrated for 185/70R13, an indicated 60 mph is actually 60.6 mph on 195/55R15, and revolutions per mile change from 869 to 860.

195/55R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 185/70R13.

Size pages

Other comparisons with 185/70R13

Other comparisons with 195/55R15

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