225/70R16 vs 225/60R18

225/60R18 is 0.23 in (5.8 mm) taller than 225/70R16, a +0.80% diameter difference. With the speedometer set for 225/70R16, an indicated 60 mph is 60.5 mph on 225/60R18.

Is this a safe swap?

Diameter difference +0.80%: under 1%

By overall diameter alone, 225/60R18 is a near match for 225/70R16; 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.

225/70R16 vs 225/60R18 differences
Measurement	225/70R16	225/60R18	Difference	% diff
Overall diameter	28.40 in (721.4 mm)	28.63 in (727.2 mm)	+0.23 in (+5.8 mm)	+0.80%
Sidewall height	6.20 in (157.5 mm)	5.31 in (135.0 mm)	−0.89 in (−22.5 mm)	−14.29%
Section width	8.86 in (225.0 mm)	8.86 in (225.0 mm)	0.00 in (0.0 mm)	0.00%
Circumference	89.23 in (2,266.3 mm)	89.94 in (2,284.6 mm)	+0.72 in (+18.2 mm)	+0.80%
Revolutions per mile	710	704	−6	−0.80%

True speed with the speedometer calibrated for 225/70R16
Indicated	Actual on 225/70R16	Actual on 225/60R18	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.5 mph	+0.5 mph
75 mph	75.0 mph	75.6 mph	+0.6 mph

Ride-height change: 225/60R18 raises the vehicle by 0.11 in (2.9 mm) at the axle (half the +5.8 mm diameter difference).

225/60R18 is 0.23 in taller than 225/70R16 and the same width, a 0.80% difference in overall diameter.

With the speedometer calibrated for 225/70R16, an indicated 60 mph is actually 60.5 mph on 225/60R18, and revolutions per mile change from 710 to 704.

225/60R18 mounts on a 18-inch wheel, a plus-2 fitment from the 16-inch wheel of 225/70R16.

Size pages

Other comparisons with 225/70R16

Other comparisons with 225/60R18

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