265/50R19 vs 245/50R20

245/50R20 is 0.21 in (5.4 mm) taller than 265/50R19, a +0.72% diameter difference. With the speedometer set for 265/50R19, an indicated 60 mph is 60.4 mph on 245/50R20.

Is this a safe swap?

Diameter difference +0.72%: under 1%

By overall diameter alone, 245/50R20 is a near match for 265/50R19; 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.

265/50R19 vs 245/50R20 differences
Measurement	265/50R19	245/50R20	Difference	% diff
Overall diameter	29.43 in (747.6 mm)	29.65 in (753.0 mm)	+0.21 in (+5.4 mm)	+0.72%
Sidewall height	5.22 in (132.5 mm)	4.82 in (122.5 mm)	−0.39 in (−10.0 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	92.47 in (2,348.7 mm)	93.13 in (2,365.6 mm)	+0.67 in (+17.0 mm)	+0.72%
Revolutions per mile	685	680	−5	−0.72%

True speed with the speedometer calibrated for 265/50R19
Indicated	Actual on 265/50R19	Actual on 245/50R20	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.4 mph	+0.4 mph
75 mph	75.0 mph	75.5 mph	+0.5 mph

Ride-height change: 245/50R20 raises the vehicle by 0.11 in (2.7 mm) at the axle (half the +5.4 mm diameter difference).

245/50R20 is 0.21 in taller than 265/50R19 and 20 mm narrower, a 0.72% difference in overall diameter.

With the speedometer calibrated for 265/50R19, an indicated 60 mph is actually 60.4 mph on 245/50R20, and revolutions per mile change from 685 to 680.

245/50R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 265/50R19.

Size pages

Other comparisons with 265/50R19

Other comparisons with 245/50R20

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