275/35R18 vs 245/35R19

245/35R19 is 0.17 in (4.4 mm) taller than 275/35R18, a +0.68% diameter difference. With the speedometer set for 275/35R18, an indicated 60 mph is 60.4 mph on 245/35R19.

Is this a safe swap?

Diameter difference +0.68%: under 1%

By overall diameter alone, 245/35R19 is a near match for 275/35R18; 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: 275/35R18 (25.58 in) vs 245/35R19 (25.75 in)275/35R1825.58 in × 10.83 in245/35R1925.75 in × 9.65 in
Side profile and tread width, drawn to the same scale.
275/35R18 vs 245/35R19 differences
Measurement275/35R18245/35R19Difference% diff
Overall diameter25.58 in (649.7 mm)25.75 in (654.1 mm)+0.17 in (+4.4 mm)+0.68%
Sidewall height3.79 in (96.3 mm)3.38 in (85.8 mm)−0.41 in (−10.5 mm)−10.91%
Section width10.83 in (275.0 mm)9.65 in (245.0 mm)−1.18 in (−30.0 mm)−10.91%
Circumference80.36 in (2,041.1 mm)80.90 in (2,054.9 mm)+0.54 in (+13.8 mm)+0.68%
Revolutions per mile788783−5−0.67%
True speed with the speedometer calibrated for 275/35R18
IndicatedActual on 275/35R18Actual on 245/35R19Difference
30 mph30.0 mph30.2 mph+0.2 mph
60 mph60.0 mph60.4 mph+0.4 mph
75 mph75.0 mph75.5 mph+0.5 mph

Ride-height change: 245/35R19 raises the vehicle by 0.09 in (2.2 mm) at the axle (half the +4.4 mm diameter difference).

245/35R19 is 0.17 in taller than 275/35R18 and 30 mm narrower, a 0.68% difference in overall diameter.

With the speedometer calibrated for 275/35R18, an indicated 60 mph is actually 60.4 mph on 245/35R19, and revolutions per mile change from 788 to 783.

245/35R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 275/35R18.

Size pages

Other comparisons with 275/35R18

Other comparisons with 245/35R19

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