235/55R19 vs 245/55R19

245/55R19 is 0.43 in (11.0 mm) taller than 235/55R19, a +1.48% diameter difference. With the speedometer set for 235/55R19, an indicated 60 mph is 60.9 mph on 245/55R19.

Is this a safe swap?

Diameter difference +1.48%: within the ±3% guideline

By overall diameter alone, 245/55R19 falls inside the ±3% range commonly used as a guideline when replacing 235/55R19. 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.

235/55R19 vs 245/55R19 differences
Measurement	235/55R19	245/55R19	Difference	% diff
Overall diameter	29.18 in (741.1 mm)	29.61 in (752.1 mm)	+0.43 in (+11.0 mm)	+1.48%
Sidewall height	5.09 in (129.3 mm)	5.31 in (134.8 mm)	+0.22 in (+5.5 mm)	+4.26%
Section width	9.25 in (235.0 mm)	9.65 in (245.0 mm)	+0.39 in (+10.0 mm)	+4.26%
Circumference	91.66 in (2,328.2 mm)	93.02 in (2,362.8 mm)	+1.36 in (+34.6 mm)	+1.48%
Revolutions per mile	691	681	−10	−1.46%

True speed with the speedometer calibrated for 235/55R19
Indicated	Actual on 235/55R19	Actual on 245/55R19	Difference
30 mph	30.0 mph	30.4 mph	+0.4 mph
60 mph	60.0 mph	60.9 mph	+0.9 mph
75 mph	75.0 mph	76.1 mph	+1.1 mph

Ride-height change: 245/55R19 raises the vehicle by 0.22 in (5.5 mm) at the axle (half the +11.0 mm diameter difference).

245/55R19 is 0.43 in taller than 235/55R19 and 10 mm wider, a 1.48% difference in overall diameter.

With the speedometer calibrated for 235/55R19, an indicated 60 mph is actually 60.9 mph on 245/55R19, and revolutions per mile change from 691 to 681.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 235/55R19

Other comparisons with 245/55R19

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