265/55R19 vs 275/50R20

275/50R20 is 0.35 in (8.9 mm) taller than 265/55R19, a +1.15% diameter difference. With the speedometer set for 265/55R19, an indicated 60 mph is 60.7 mph on 275/50R20.

Is this a safe swap?

Diameter difference +1.15%: within the ±3% guideline

By overall diameter alone, 275/50R20 falls inside the ±3% range commonly used as a guideline when replacing 265/55R19. 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.

265/55R19 vs 275/50R20 differences
Measurement	265/55R19	275/50R20	Difference	% diff
Overall diameter	30.48 in (774.1 mm)	30.83 in (783.0 mm)	+0.35 in (+8.9 mm)	+1.15%
Sidewall height	5.74 in (145.8 mm)	5.41 in (137.5 mm)	−0.32 in (−8.2 mm)	−5.66%
Section width	10.43 in (265.0 mm)	10.83 in (275.0 mm)	+0.39 in (+10.0 mm)	+3.77%
Circumference	95.74 in (2,431.9 mm)	96.85 in (2,459.9 mm)	+1.10 in (+28.0 mm)	+1.15%
Revolutions per mile	662	654	−8	−1.14%

True speed with the speedometer calibrated for 265/55R19
Indicated	Actual on 265/55R19	Actual on 275/50R20	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.7 mph	+0.7 mph
75 mph	75.0 mph	75.9 mph	+0.9 mph

Ride-height change: 275/50R20 raises the vehicle by 0.18 in (4.5 mm) at the axle (half the +8.9 mm diameter difference).

275/50R20 is 0.35 in taller than 265/55R19 and 10 mm wider, a 1.15% difference in overall diameter.

With the speedometer calibrated for 265/55R19, an indicated 60 mph is actually 60.7 mph on 275/50R20, and revolutions per mile change from 662 to 654.

275/50R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 265/55R19.

Size pages

Other comparisons with 265/55R19

Other comparisons with 275/50R20

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