285/55R20 vs 265/60R20

265/60R20 is 0.18 in (4.5 mm) taller than 285/55R20, a +0.55% diameter difference. With the speedometer set for 285/55R20, an indicated 60 mph is 60.3 mph on 265/60R20.

Is this a safe swap?

Diameter difference +0.55%: under 1%

By overall diameter alone, 265/60R20 is a near match for 285/55R20; 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.

285/55R20 vs 265/60R20 differences
Measurement	285/55R20	265/60R20	Difference	% diff
Overall diameter	32.34 in (821.5 mm)	32.52 in (826.0 mm)	+0.18 in (+4.5 mm)	+0.55%
Sidewall height	6.17 in (156.8 mm)	6.26 in (159.0 mm)	+0.09 in (+2.3 mm)	+1.44%
Section width	11.22 in (285.0 mm)	10.43 in (265.0 mm)	−0.79 in (−20.0 mm)	−7.02%
Circumference	101.61 in (2,580.8 mm)	102.16 in (2,595.0 mm)	+0.56 in (+14.1 mm)	+0.55%
Revolutions per mile	624	620	−3	−0.54%

True speed with the speedometer calibrated for 285/55R20
Indicated	Actual on 285/55R20	Actual on 265/60R20	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 265/60R20 raises the vehicle by 0.09 in (2.3 mm) at the axle (half the +4.5 mm diameter difference).

265/60R20 is 0.18 in taller than 285/55R20 and 20 mm narrower, a 0.55% difference in overall diameter.

With the speedometer calibrated for 285/55R20, an indicated 60 mph is actually 60.3 mph on 265/60R20, and revolutions per mile change from 624 to 620.

Both sizes mount on 20-inch wheels.

Size pages

Other comparisons with 285/55R20

Other comparisons with 265/60R20

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