TireSizesFinder

245/55R19 vs 255/55R19

255/55R19 is 0.43 in (11.0 mm) taller than 245/55R19, a +1.46% diameter difference. With the speedometer set for 245/55R19, an indicated 60 mph is 60.9 mph on 255/55R19.

Is this a safe swap?

Diameter difference +1.46%: within the ±3% guideline

By overall diameter alone, 255/55R19 falls inside the ±3% range commonly used as a guideline when replacing 245/55R19. 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 255/55R19 (30.04 in)245/55R1929.61 in × 9.65 in255/55R1930.04 in × 10.04 in
Side profile and tread width, drawn to the same scale.
245/55R19 vs 255/55R19 differences
Measurement245/55R19255/55R19Difference% diff
Overall diameter29.61 in (752.1 mm)30.04 in (763.1 mm)+0.43 in (+11.0 mm)+1.46%
Sidewall height5.31 in (134.8 mm)5.52 in (140.3 mm)+0.22 in (+5.5 mm)+4.08%
Section width9.65 in (245.0 mm)10.04 in (255.0 mm)+0.39 in (+10.0 mm)+4.08%
Circumference93.02 in (2,362.8 mm)94.38 in (2,397.3 mm)+1.36 in (+34.6 mm)+1.46%
Revolutions per mile681671−10−1.44%
True speed with the speedometer calibrated for 245/55R19
IndicatedActual on 245/55R19Actual on 255/55R19Difference
30 mph30.0 mph30.4 mph+0.4 mph
60 mph60.0 mph60.9 mph+0.9 mph
75 mph75.0 mph76.1 mph+1.1 mph

Ride-height change: 255/55R19 raises the vehicle by 0.22 in (5.5 mm) at the axle (half the +11.0 mm diameter difference).

255/55R19 is 0.43 in taller than 245/55R19 and 10 mm wider, a 1.46% difference in overall diameter.

With the speedometer calibrated for 245/55R19, an indicated 60 mph is actually 60.9 mph on 255/55R19, and revolutions per mile change from 681 to 671.

Both sizes mount on 19-inch wheels.

Size pages

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