245/65R18 vs 265/55R19

265/55R19 is 0.06 in (1.6 mm) shorter than 245/65R18, a −0.21% diameter difference. With the speedometer set for 245/65R18, an indicated 60 mph is 59.9 mph on 265/55R19.

Is this a safe swap?

Diameter difference −0.21%: under 1%

By overall diameter alone, 265/55R19 is a near match for 245/65R18; 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: 245/65R18 (30.54 in) vs 265/55R19 (30.48 in)245/65R1830.54 in × 9.65 in265/55R1930.48 in × 10.43 in
Side profile and tread width, drawn to the same scale.
245/65R18 vs 265/55R19 differences
Measurement245/65R18265/55R19Difference% diff
Overall diameter30.54 in (775.7 mm)30.48 in (774.1 mm)−0.06 in (−1.6 mm)−0.21%
Sidewall height6.27 in (159.3 mm)5.74 in (145.8 mm)−0.53 in (−13.5 mm)−8.48%
Section width9.65 in (245.0 mm)10.43 in (265.0 mm)+0.79 in (+20.0 mm)+8.16%
Circumference95.94 in (2,436.9 mm)95.74 in (2,431.9 mm)−0.20 in (−5.0 mm)−0.21%
Revolutions per mile660662+1+0.21%
True speed with the speedometer calibrated for 245/65R18
IndicatedActual on 245/65R18Actual on 265/55R19Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.9 mph−0.1 mph
75 mph75.0 mph74.8 mph−0.2 mph

Ride-height change: 265/55R19 lowers the vehicle by 0.03 in (0.8 mm) at the axle (half the −1.6 mm diameter difference).

265/55R19 is 0.06 in shorter than 245/65R18 and 20 mm wider, a 0.21% difference in overall diameter.

With the speedometer calibrated for 245/65R18, an indicated 60 mph is actually 59.9 mph on 265/55R19, and revolutions per mile change from 660 to 662.

265/55R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 245/65R18.

Size pages

Other comparisons with 245/65R18

Other comparisons with 265/55R19

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