175/65R14 vs 205/50R15

205/50R15 is 0.11 in (2.9 mm) taller than 175/65R14, a +0.50% diameter difference. With the speedometer set for 175/65R14, an indicated 60 mph is 60.3 mph on 205/50R15.

Is this a safe swap?

Diameter difference +0.50%: under 1%

By overall diameter alone, 205/50R15 is a near match for 175/65R14; 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.

175/65R14 vs 205/50R15 differences
Measurement	175/65R14	205/50R15	Difference	% diff
Overall diameter	22.96 in (583.1 mm)	23.07 in (586.0 mm)	+0.11 in (+2.9 mm)	+0.50%
Sidewall height	4.48 in (113.8 mm)	4.04 in (102.5 mm)	−0.44 in (−11.2 mm)	−9.89%
Section width	6.89 in (175.0 mm)	8.07 in (205.0 mm)	+1.18 in (+30.0 mm)	+17.14%
Circumference	72.12 in (1,831.9 mm)	72.48 in (1,841.0 mm)	+0.36 in (+9.1 mm)	+0.50%
Revolutions per mile	879	874	−4	−0.49%

True speed with the speedometer calibrated for 175/65R14
Indicated	Actual on 175/65R14	Actual on 205/50R15	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 205/50R15 raises the vehicle by 0.06 in (1.5 mm) at the axle (half the +2.9 mm diameter difference).

205/50R15 is 0.11 in taller than 175/65R14 and 30 mm wider, a 0.50% difference in overall diameter.

With the speedometer calibrated for 175/65R14, an indicated 60 mph is actually 60.3 mph on 205/50R15, and revolutions per mile change from 879 to 874.

205/50R15 mounts on a 15-inch wheel, a plus-1 fitment from the 14-inch wheel of 175/65R14.

Size pages

Other comparisons with 175/65R14

Other comparisons with 205/50R15

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