225/75R17 vs 265/60R18

265/60R18 is 0.23 in (5.9 mm) taller than 225/75R17, a +0.77% diameter difference. With the speedometer set for 225/75R17, an indicated 60 mph is 60.5 mph on 265/60R18.

Is this a safe swap?

Diameter difference +0.77%: under 1%

By overall diameter alone, 265/60R18 is a near match for 225/75R17; 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.

225/75R17 vs 265/60R18 differences
Measurement	225/75R17	265/60R18	Difference	% diff
Overall diameter	30.29 in (769.3 mm)	30.52 in (775.2 mm)	+0.23 in (+5.9 mm)	+0.77%
Sidewall height	6.64 in (168.8 mm)	6.26 in (159.0 mm)	−0.38 in (−9.7 mm)	−5.78%
Section width	8.86 in (225.0 mm)	10.43 in (265.0 mm)	+1.57 in (+40.0 mm)	+17.78%
Circumference	95.15 in (2,416.8 mm)	95.88 in (2,435.4 mm)	+0.73 in (+18.5 mm)	+0.77%
Revolutions per mile	666	661	−5	−0.76%

True speed with the speedometer calibrated for 225/75R17
Indicated	Actual on 225/75R17	Actual on 265/60R18	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: 265/60R18 raises the vehicle by 0.12 in (3.0 mm) at the axle (half the +5.9 mm diameter difference).

265/60R18 is 0.23 in taller than 225/75R17 and 40 mm wider, a 0.77% difference in overall diameter.

With the speedometer calibrated for 225/75R17, an indicated 60 mph is actually 60.5 mph on 265/60R18, and revolutions per mile change from 666 to 661.

265/60R18 mounts on a 18-inch wheel, a plus-1 fitment from the 17-inch wheel of 225/75R17.

Size pages

Other comparisons with 225/75R17

Other comparisons with 265/60R18

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