265/55R19 vs 245/55R20

245/55R20 is 0.13 in (3.4 mm) taller than 265/55R19, a +0.44% diameter difference. With the speedometer set for 265/55R19, an indicated 60 mph is 60.3 mph on 245/55R20.

Is this a safe swap?

Diameter difference +0.44%: under 1%

By overall diameter alone, 245/55R20 is a near match for 265/55R19; 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.

265/55R19 vs 245/55R20 differences
Measurement	265/55R19	245/55R20	Difference	% diff
Overall diameter	30.48 in (774.1 mm)	30.61 in (777.5 mm)	+0.13 in (+3.4 mm)	+0.44%
Sidewall height	5.74 in (145.8 mm)	5.31 in (134.8 mm)	−0.43 in (−11.0 mm)	−7.55%
Section width	10.43 in (265.0 mm)	9.65 in (245.0 mm)	−0.79 in (−20.0 mm)	−7.55%
Circumference	95.74 in (2,431.9 mm)	96.16 in (2,442.6 mm)	+0.42 in (+10.7 mm)	+0.44%
Revolutions per mile	662	659	−3	−0.44%

True speed with the speedometer calibrated for 265/55R19
Indicated	Actual on 265/55R19	Actual on 245/55R20	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.3 mph	+0.3 mph

Ride-height change: 245/55R20 raises the vehicle by 0.07 in (1.7 mm) at the axle (half the +3.4 mm diameter difference).

245/55R20 is 0.13 in taller than 265/55R19 and 20 mm narrower, a 0.44% difference in overall diameter.

With the speedometer calibrated for 265/55R19, an indicated 60 mph is actually 60.3 mph on 245/55R20, and revolutions per mile change from 662 to 659.

245/55R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 265/55R19.

Size pages

Other comparisons with 265/55R19

Other comparisons with 245/55R20

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