215/75R16 vs 225/60R18

225/60R18 is 0.07 in (1.7 mm) shorter than 215/75R16, a −0.23% diameter difference. With the speedometer set for 215/75R16, an indicated 60 mph is 59.9 mph on 225/60R18.

Is this a safe swap?

Diameter difference −0.23%: under 1%

By overall diameter alone, 225/60R18 is a near match for 215/75R16; 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.

215/75R16 vs 225/60R18 differences
Measurement	215/75R16	225/60R18	Difference	% diff
Overall diameter	28.70 in (728.9 mm)	28.63 in (727.2 mm)	−0.07 in (−1.7 mm)	−0.23%
Sidewall height	6.35 in (161.3 mm)	5.31 in (135.0 mm)	−1.03 in (−26.2 mm)	−16.28%
Section width	8.46 in (215.0 mm)	8.86 in (225.0 mm)	+0.39 in (+10.0 mm)	+4.65%
Circumference	90.15 in (2,289.9 mm)	89.94 in (2,284.6 mm)	−0.21 in (−5.3 mm)	−0.23%
Revolutions per mile	703	704	+2	+0.23%

True speed with the speedometer calibrated for 215/75R16
Indicated	Actual on 215/75R16	Actual on 225/60R18	Difference
30 mph	30.0 mph	29.9 mph	−0.1 mph
60 mph	60.0 mph	59.9 mph	−0.1 mph
75 mph	75.0 mph	74.8 mph	−0.2 mph

Ride-height change: 225/60R18 lowers the vehicle by 0.03 in (0.8 mm) at the axle (half the −1.7 mm diameter difference).

225/60R18 is 0.07 in shorter than 215/75R16 and 10 mm wider, a 0.23% difference in overall diameter.

With the speedometer calibrated for 215/75R16, an indicated 60 mph is actually 59.9 mph on 225/60R18, and revolutions per mile change from 703 to 704.

225/60R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 215/75R16.

Size pages

Other comparisons with 215/75R16

Other comparisons with 225/60R18

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