185/70R13 vs 185/65R14

185/65R14 is 0.27 in (6.9 mm) taller than 185/70R13, a +1.17% diameter difference. With the speedometer set for 185/70R13, an indicated 60 mph is 60.7 mph on 185/65R14.

Is this a safe swap?

Diameter difference +1.17%: within the ±3% guideline

By overall diameter alone, 185/65R14 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 185/65R14 differences
Measurement	185/70R13	185/65R14	Difference	% diff
Overall diameter	23.20 in (589.2 mm)	23.47 in (596.1 mm)	+0.27 in (+6.9 mm)	+1.17%
Sidewall height	5.10 in (129.5 mm)	4.73 in (120.3 mm)	−0.36 in (−9.2 mm)	−7.14%
Section width	7.28 in (185.0 mm)	7.28 in (185.0 mm)	0.00 in (0.0 mm)	0.00%
Circumference	72.88 in (1,851.0 mm)	73.73 in (1,872.7 mm)	+0.85 in (+21.7 mm)	+1.17%
Revolutions per mile	869	859	−10	−1.16%

True speed with the speedometer calibrated for 185/70R13
Indicated	Actual on 185/70R13	Actual on 185/65R14	Difference
30 mph	30.0 mph	30.4 mph	+0.4 mph
60 mph	60.0 mph	60.7 mph	+0.7 mph
75 mph	75.0 mph	75.9 mph	+0.9 mph

Ride-height change: 185/65R14 raises the vehicle by 0.14 in (3.4 mm) at the axle (half the +6.9 mm diameter difference).

185/65R14 is 0.27 in taller than 185/70R13 and the same width, a 1.17% difference in overall diameter.

With the speedometer calibrated for 185/70R13, an indicated 60 mph is actually 60.7 mph on 185/65R14, and revolutions per mile change from 869 to 859.

185/65R14 mounts on a 14-inch wheel, a plus-1 fitment from the 13-inch wheel of 185/70R13.

Size pages

Other comparisons with 185/70R13

Other comparisons with 185/65R14

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