195/50R15 vs 225/40R16

225/40R16 is 0.41 in (10.4 mm) taller than 195/50R15, a +1.81% diameter difference. With the speedometer set for 195/50R15, an indicated 60 mph is 61.1 mph on 225/40R16.

Is this a safe swap?

Diameter difference +1.81%: within the ±3% guideline

By overall diameter alone, 225/40R16 falls inside the ±3% range commonly used as a guideline when replacing 195/50R15. 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.

195/50R15 vs 225/40R16 differences
Measurement	195/50R15	225/40R16	Difference	% diff
Overall diameter	22.68 in (576.0 mm)	23.09 in (586.4 mm)	+0.41 in (+10.4 mm)	+1.81%
Sidewall height	3.84 in (97.5 mm)	3.54 in (90.0 mm)	−0.30 in (−7.5 mm)	−7.69%
Section width	7.68 in (195.0 mm)	8.86 in (225.0 mm)	+1.18 in (+30.0 mm)	+15.38%
Circumference	71.24 in (1,809.6 mm)	72.53 in (1,842.2 mm)	+1.29 in (+32.7 mm)	+1.81%
Revolutions per mile	889	874	−16	−1.77%

True speed with the speedometer calibrated for 195/50R15
Indicated	Actual on 195/50R15	Actual on 225/40R16	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	61.1 mph	+1.1 mph
75 mph	75.0 mph	76.4 mph	+1.4 mph

Ride-height change: 225/40R16 raises the vehicle by 0.20 in (5.2 mm) at the axle (half the +10.4 mm diameter difference).

225/40R16 is 0.41 in taller than 195/50R15 and 30 mm wider, a 1.81% difference in overall diameter.

With the speedometer calibrated for 195/50R15, an indicated 60 mph is actually 61.1 mph on 225/40R16, and revolutions per mile change from 889 to 874.

225/40R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 195/50R15.

Size pages

Other comparisons with 195/50R15

Other comparisons with 225/40R16

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