195/50R16 vs 215/35R18

215/35R18 is 0.25 in (6.3 mm) taller than 195/50R16, a +1.05% diameter difference. With the speedometer set for 195/50R16, an indicated 60 mph is 60.6 mph on 215/35R18.

Is this a safe swap?

Diameter difference +1.05%: within the ±3% guideline

By overall diameter alone, 215/35R18 falls inside the ±3% range commonly used as a guideline when replacing 195/50R16. 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.

195/50R16 vs 215/35R18 differences
Measurement	195/50R16	215/35R18	Difference	% diff
Overall diameter	23.68 in (601.4 mm)	23.93 in (607.7 mm)	+0.25 in (+6.3 mm)	+1.05%
Sidewall height	3.84 in (97.5 mm)	2.96 in (75.3 mm)	−0.88 in (−22.2 mm)	−22.82%
Section width	7.68 in (195.0 mm)	8.46 in (215.0 mm)	+0.79 in (+20.0 mm)	+10.26%
Circumference	74.38 in (1,889.4 mm)	75.16 in (1,909.1 mm)	+0.78 in (+19.8 mm)	+1.05%
Revolutions per mile	852	843	−9	−1.04%

True speed with the speedometer calibrated for 195/50R16
Indicated	Actual on 195/50R16	Actual on 215/35R18	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.6 mph	+0.6 mph
75 mph	75.0 mph	75.8 mph	+0.8 mph

Ride-height change: 215/35R18 raises the vehicle by 0.12 in (3.2 mm) at the axle (half the +6.3 mm diameter difference).

215/35R18 is 0.25 in taller than 195/50R16 and 20 mm wider, a 1.05% difference in overall diameter.

With the speedometer calibrated for 195/50R16, an indicated 60 mph is actually 60.6 mph on 215/35R18, and revolutions per mile change from 852 to 843.

215/35R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 195/50R16.

Size pages

Other comparisons with 195/50R16

Other comparisons with 215/35R18

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