275/50R19 vs 255/55R19

255/55R19 is 0.22 in (5.5 mm) taller than 275/50R19, a +0.73% diameter difference. With the speedometer set for 275/50R19, an indicated 60 mph is 60.4 mph on 255/55R19.

Is this a safe swap?

Diameter difference +0.73%: under 1%

By overall diameter alone, 255/55R19 is a near match for 275/50R19; 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.

275/50R19 vs 255/55R19 differences
Measurement	275/50R19	255/55R19	Difference	% diff
Overall diameter	29.83 in (757.6 mm)	30.04 in (763.1 mm)	+0.22 in (+5.5 mm)	+0.73%
Sidewall height	5.41 in (137.5 mm)	5.52 in (140.3 mm)	+0.11 in (+2.8 mm)	+2.00%
Section width	10.83 in (275.0 mm)	10.04 in (255.0 mm)	−0.79 in (−20.0 mm)	−7.27%
Circumference	93.70 in (2,380.1 mm)	94.38 in (2,397.3 mm)	+0.68 in (+17.3 mm)	+0.73%
Revolutions per mile	676	671	−5	−0.72%

True speed with the speedometer calibrated for 275/50R19
Indicated	Actual on 275/50R19	Actual on 255/55R19	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: 255/55R19 raises the vehicle by 0.11 in (2.8 mm) at the axle (half the +5.5 mm diameter difference).

255/55R19 is 0.22 in taller than 275/50R19 and 20 mm narrower, a 0.73% difference in overall diameter.

With the speedometer calibrated for 275/50R19, an indicated 60 mph is actually 60.4 mph on 255/55R19, and revolutions per mile change from 676 to 671.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 275/50R19

Other comparisons with 255/55R19

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