185/60R14 vs 225/40R16

225/40R16 is 0.35 in (8.8 mm) taller than 185/60R14, a +1.52% diameter difference. With the speedometer set for 185/60R14, an indicated 60 mph is 60.9 mph on 225/40R16.

Is this a safe swap?

Diameter difference +1.52%: within the ±3% guideline

By overall diameter alone, 225/40R16 falls inside the ±3% range commonly used as a guideline when replacing 185/60R14. 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.

185/60R14 vs 225/40R16 differences
Measurement	185/60R14	225/40R16	Difference	% diff
Overall diameter	22.74 in (577.6 mm)	23.09 in (586.4 mm)	+0.35 in (+8.8 mm)	+1.52%
Sidewall height	4.37 in (111.0 mm)	3.54 in (90.0 mm)	−0.83 in (−21.0 mm)	−18.92%
Section width	7.28 in (185.0 mm)	8.86 in (225.0 mm)	+1.57 in (+40.0 mm)	+21.62%
Circumference	71.44 in (1,814.6 mm)	72.53 in (1,842.2 mm)	+1.09 in (+27.6 mm)	+1.52%
Revolutions per mile	887	874	−13	−1.50%

True speed with the speedometer calibrated for 185/60R14
Indicated	Actual on 185/60R14	Actual on 225/40R16	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	60.9 mph	+0.9 mph
75 mph	75.0 mph	76.1 mph	+1.1 mph

Ride-height change: 225/40R16 raises the vehicle by 0.17 in (4.4 mm) at the axle (half the +8.8 mm diameter difference).

225/40R16 is 0.35 in taller than 185/60R14 and 40 mm wider, a 1.52% difference in overall diameter.

With the speedometer calibrated for 185/60R14, an indicated 60 mph is actually 60.9 mph on 225/40R16, and revolutions per mile change from 887 to 874.

225/40R16 mounts on a 16-inch wheel, a plus-2 fitment from the 14-inch wheel of 185/60R14.

Size pages

Other comparisons with 185/60R14

Other comparisons with 225/40R16

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