285/60R18 vs 265/65R18

265/65R18 is 0.10 in (2.5 mm) taller than 285/60R18, a +0.31% diameter difference. With the speedometer set for 285/60R18, an indicated 60 mph is 60.2 mph on 265/65R18.

Is this a safe swap?

Diameter difference +0.31%: under 1%

By overall diameter alone, 265/65R18 is a near match for 285/60R18; 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.

285/60R18 vs 265/65R18 differences
Measurement	285/60R18	265/65R18	Difference	% diff
Overall diameter	31.46 in (799.2 mm)	31.56 in (801.7 mm)	+0.10 in (+2.5 mm)	+0.31%
Sidewall height	6.73 in (171.0 mm)	6.78 in (172.3 mm)	+0.05 in (+1.3 mm)	+0.73%
Section width	11.22 in (285.0 mm)	10.43 in (265.0 mm)	−0.79 in (−20.0 mm)	−7.02%
Circumference	98.85 in (2,510.8 mm)	99.16 in (2,518.6 mm)	+0.31 in (+7.9 mm)	+0.31%
Revolutions per mile	641	639	−2	−0.31%

True speed with the speedometer calibrated for 285/60R18
Indicated	Actual on 285/60R18	Actual on 265/65R18	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.2 mph	+0.2 mph
75 mph	75.0 mph	75.2 mph	+0.2 mph

Ride-height change: 265/65R18 raises the vehicle by 0.05 in (1.3 mm) at the axle (half the +2.5 mm diameter difference).

265/65R18 is 0.10 in taller than 285/60R18 and 20 mm narrower, a 0.31% difference in overall diameter.

With the speedometer calibrated for 285/60R18, an indicated 60 mph is actually 60.2 mph on 265/65R18, and revolutions per mile change from 641 to 639.

Both sizes mount on 18-inch wheels.

Size pages

Other comparisons with 285/60R18

Other comparisons with 265/65R18

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