255/60R20 vs 265/60R20

265/60R20 is 0.47 in (12.0 mm) taller than 255/60R20, a +1.47% diameter difference. With the speedometer set for 255/60R20, an indicated 60 mph is 60.9 mph on 265/60R20.

Is this a safe swap?

Diameter difference +1.47%: within the ±3% guideline

By overall diameter alone, 265/60R20 falls inside the ±3% range commonly used as a guideline when replacing 255/60R20. 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.

255/60R20 vs 265/60R20 differences
Measurement	255/60R20	265/60R20	Difference	% diff
Overall diameter	32.05 in (814.0 mm)	32.52 in (826.0 mm)	+0.47 in (+12.0 mm)	+1.47%
Sidewall height	6.02 in (153.0 mm)	6.26 in (159.0 mm)	+0.24 in (+6.0 mm)	+3.92%
Section width	10.04 in (255.0 mm)	10.43 in (265.0 mm)	+0.39 in (+10.0 mm)	+3.92%
Circumference	100.68 in (2,557.3 mm)	102.16 in (2,595.0 mm)	+1.48 in (+37.7 mm)	+1.47%
Revolutions per mile	629	620	−9	−1.45%

True speed with the speedometer calibrated for 255/60R20
Indicated	Actual on 255/60R20	Actual on 265/60R20	Difference
30 mph	30.0 mph	30.4 mph	+0.4 mph
60 mph	60.0 mph	60.9 mph	+0.9 mph
75 mph	75.0 mph	76.1 mph	+1.1 mph

Ride-height change: 265/60R20 raises the vehicle by 0.24 in (6.0 mm) at the axle (half the +12.0 mm diameter difference).

265/60R20 is 0.47 in taller than 255/60R20 and 10 mm wider, a 1.47% difference in overall diameter.

With the speedometer calibrated for 255/60R20, an indicated 60 mph is actually 60.9 mph on 265/60R20, and revolutions per mile change from 629 to 620.

Both sizes mount on 20-inch wheels.

Size pages

Other comparisons with 255/60R20

Other comparisons with 265/60R20

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