TireSizesFinder

225/45R18 vs 245/35R19

245/35R19 is 0.22 in (5.6 mm) shorter than 225/45R18, a −0.85% diameter difference. With the speedometer set for 225/45R18, an indicated 60 mph is 59.5 mph on 245/35R19.

Is this a safe swap?

Diameter difference −0.85%: under 1%

By overall diameter alone, 245/35R19 is a near match for 225/45R18; 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: 225/45R18 (25.97 in) vs 245/35R19 (25.75 in)225/45R1825.97 in × 8.86 in245/35R1925.75 in × 9.65 in
Side profile and tread width, drawn to the same scale.
225/45R18 vs 245/35R19 differences
Measurement225/45R18245/35R19Difference% diff
Overall diameter25.97 in (659.7 mm)25.75 in (654.1 mm)−0.22 in (−5.6 mm)−0.85%
Sidewall height3.99 in (101.3 mm)3.38 in (85.8 mm)−0.61 in (−15.5 mm)−15.31%
Section width8.86 in (225.0 mm)9.65 in (245.0 mm)+0.79 in (+20.0 mm)+8.89%
Circumference81.59 in (2,072.5 mm)80.90 in (2,054.9 mm)−0.69 in (−17.6 mm)−0.85%
Revolutions per mile777783+7+0.86%
True speed with the speedometer calibrated for 225/45R18
IndicatedActual on 225/45R18Actual on 245/35R19Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 245/35R19 lowers the vehicle by 0.11 in (2.8 mm) at the axle (half the −5.6 mm diameter difference).

245/35R19 is 0.22 in shorter than 225/45R18 and 20 mm wider, a 0.85% difference in overall diameter.

With the speedometer calibrated for 225/45R18, an indicated 60 mph is actually 59.5 mph on 245/35R19, and revolutions per mile change from 777 to 783.

245/35R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 225/45R18.

Size pages

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