TireSizesFinder

245/55R18 vs 265/45R19

265/45R19 is 0.22 in (5.6 mm) shorter than 245/55R18, a −0.77% diameter difference. With the speedometer set for 245/55R18, an indicated 60 mph is 59.5 mph on 265/45R19.

Is this a safe swap?

Diameter difference −0.77%: under 1%

By overall diameter alone, 265/45R19 is a near match for 245/55R18; 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: 245/55R18 (28.61 in) vs 265/45R19 (28.39 in)245/55R1828.61 in × 9.65 in265/45R1928.39 in × 10.43 in
Side profile and tread width, drawn to the same scale.
245/55R18 vs 265/45R19 differences
Measurement245/55R18265/45R19Difference% diff
Overall diameter28.61 in (726.7 mm)28.39 in (721.1 mm)−0.22 in (−5.6 mm)−0.77%
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%
Circumference89.88 in (2,283.0 mm)89.19 in (2,265.4 mm)−0.69 in (−17.6 mm)−0.77%
Revolutions per mile705710+5+0.78%
True speed with the speedometer calibrated for 245/55R18
IndicatedActual on 245/55R18Actual on 265/45R19Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 265/45R19 lowers the vehicle by 0.11 in (2.8 mm) at the axle (half the −5.6 mm diameter difference).

265/45R19 is 0.22 in shorter than 245/55R18 and 20 mm wider, a 0.77% difference in overall diameter.

With the speedometer calibrated for 245/55R18, an indicated 60 mph is actually 59.5 mph on 265/45R19, and revolutions per mile change from 705 to 710.

265/45R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 245/55R18.

Size pages

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