265/60R18 vs 245/65R18

245/65R18 is 0.02 in (0.5 mm) taller than 265/60R18, a +0.06% diameter difference. With the speedometer set for 265/60R18, an indicated 60 mph is 60.0 mph on 245/65R18.

Is this a safe swap?

Diameter difference +0.06%: under 1%

By overall diameter alone, 245/65R18 is a near match for 265/60R18; 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.

265/60R18 vs 245/65R18 differences
Measurement	265/60R18	245/65R18	Difference	% diff
Overall diameter	30.52 in (775.2 mm)	30.54 in (775.7 mm)	+0.02 in (+0.5 mm)	+0.06%
Sidewall height	6.26 in (159.0 mm)	6.27 in (159.3 mm)	+0.01 in (+0.3 mm)	+0.16%
Section width	10.43 in (265.0 mm)	9.65 in (245.0 mm)	−0.79 in (−20.0 mm)	−7.55%
Circumference	95.88 in (2,435.4 mm)	95.94 in (2,436.9 mm)	+0.06 in (+1.6 mm)	+0.06%
Revolutions per mile	661	660	0	−0.06%

True speed with the speedometer calibrated for 265/60R18
Indicated	Actual on 265/60R18	Actual on 245/65R18
30 mph	30.0 mph	30.0 mph
60 mph	60.0 mph	60.0 mph
75 mph	75.0 mph	75.0 mph

Ride-height change: 245/65R18 raises the vehicle by 0.01 in (0.3 mm) at the axle (half the +0.5 mm diameter difference).

245/65R18 is 0.02 in taller than 265/60R18 and 20 mm narrower, a 0.06% difference in overall diameter.

With the speedometer calibrated for 265/60R18, an indicated 60 mph is actually 60.0 mph on 245/65R18, and revolutions per mile change from 661 to 660.

Both sizes mount on 18-inch wheels.

Size pages

Other comparisons with 265/60R18

Other comparisons with 245/65R18

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