TireSizesFinder

245/55R19 vs 265/45R20

265/45R20 is 0.22 in (5.6 mm) shorter than 245/55R19, a −0.74% diameter difference. With the speedometer set for 245/55R19, an indicated 60 mph is 59.6 mph on 265/45R20.

Is this a safe swap?

Diameter difference −0.74%: under 1%

By overall diameter alone, 265/45R20 is a near match for 245/55R19; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 245/55R19 (29.61 in) vs 265/45R20 (29.39 in)245/55R1929.61 in × 9.65 in265/45R2029.39 in × 10.43 in
Side profile and tread width, drawn to the same scale.
245/55R19 vs 265/45R20 differences
Measurement245/55R19265/45R20Difference% diff
Overall diameter29.61 in (752.1 mm)29.39 in (746.5 mm)−0.22 in (−5.6 mm)−0.74%
Sidewall height5.31 in (134.8 mm)4.69 in (119.3 mm)−0.61 in (−15.5 mm)−11.50%
Section width9.65 in (245.0 mm)10.43 in (265.0 mm)+0.79 in (+20.0 mm)+8.16%
Circumference93.02 in (2,362.8 mm)92.33 in (2,345.2 mm)−0.69 in (−17.6 mm)−0.74%
Revolutions per mile681686+5+0.75%
True speed with the speedometer calibrated for 245/55R19
IndicatedActual on 245/55R19Actual on 265/45R20Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.6 mph−0.4 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 265/45R20 lowers the vehicle by 0.11 in (2.8 mm) at the axle (half the −5.6 mm diameter difference).

265/45R20 is 0.22 in shorter than 245/55R19 and 20 mm wider, a 0.74% difference in overall diameter.

With the speedometer calibrated for 245/55R19, an indicated 60 mph is actually 59.6 mph on 265/45R20, and revolutions per mile change from 681 to 686.

265/45R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 245/55R19.

Size pages

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Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.