185/60R15 vs 225/50R15

225/50R15 is 0.12 in (3.0 mm) taller than 185/60R15, a +0.50% diameter difference. With the speedometer set for 185/60R15, an indicated 60 mph is 60.3 mph on 225/50R15.

Is this a safe swap?

Diameter difference +0.50%: under 1%

By overall diameter alone, 225/50R15 is a near match for 185/60R15; 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.

185/60R15 vs 225/50R15 differences
Measurement	185/60R15	225/50R15	Difference	% diff
Overall diameter	23.74 in (603.0 mm)	23.86 in (606.0 mm)	+0.12 in (+3.0 mm)	+0.50%
Sidewall height	4.37 in (111.0 mm)	4.43 in (112.5 mm)	+0.06 in (+1.5 mm)	+1.35%
Section width	7.28 in (185.0 mm)	8.86 in (225.0 mm)	+1.57 in (+40.0 mm)	+21.62%
Circumference	74.58 in (1,894.4 mm)	74.95 in (1,903.8 mm)	+0.37 in (+9.4 mm)	+0.50%
Revolutions per mile	850	845	−4	−0.50%

True speed with the speedometer calibrated for 185/60R15
Indicated	Actual on 185/60R15	Actual on 225/50R15	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: 225/50R15 raises the vehicle by 0.06 in (1.5 mm) at the axle (half the +3.0 mm diameter difference).

225/50R15 is 0.12 in taller than 185/60R15 and 40 mm wider, a 0.50% difference in overall diameter.

With the speedometer calibrated for 185/60R15, an indicated 60 mph is actually 60.3 mph on 225/50R15, and revolutions per mile change from 850 to 845.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 185/60R15

Other comparisons with 225/50R15

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