TireSizesFinder

255/50R17 vs 225/45R19

225/45R19 is 0.07 in (1.7 mm) shorter than 255/50R17, a −0.25% diameter difference. With the speedometer set for 255/50R17, an indicated 60 mph is 59.9 mph on 225/45R19.

Is this a safe swap?

Diameter difference −0.25%: under 1%

By overall diameter alone, 225/45R19 is a near match for 255/50R17; 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: 255/50R17 (27.04 in) vs 225/45R19 (26.97 in)255/50R1727.04 in × 10.04 in225/45R1926.97 in × 8.86 in
Side profile and tread width, drawn to the same scale.
255/50R17 vs 225/45R19 differences
Measurement255/50R17225/45R19Difference% diff
Overall diameter27.04 in (686.8 mm)26.97 in (685.1 mm)−0.07 in (−1.7 mm)−0.25%
Sidewall height5.02 in (127.5 mm)3.99 in (101.3 mm)−1.03 in (−26.2 mm)−20.59%
Section width10.04 in (255.0 mm)8.86 in (225.0 mm)−1.18 in (−30.0 mm)−11.76%
Circumference84.95 in (2,157.6 mm)84.74 in (2,152.3 mm)−0.21 in (−5.3 mm)−0.25%
Revolutions per mile746748+2+0.25%
True speed with the speedometer calibrated for 255/50R17
IndicatedActual on 255/50R17Actual on 225/45R19Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.9 mph−0.1 mph
75 mph75.0 mph74.8 mph−0.2 mph

Ride-height change: 225/45R19 lowers the vehicle by 0.03 in (0.9 mm) at the axle (half the −1.7 mm diameter difference).

225/45R19 is 0.07 in shorter than 255/50R17 and 30 mm narrower, a 0.25% difference in overall diameter.

With the speedometer calibrated for 255/50R17, an indicated 60 mph is actually 59.9 mph on 225/45R19, and revolutions per mile change from 746 to 748.

225/45R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 255/50R17.

Size pages

Other comparisons with 255/50R17

Other comparisons with 225/45R19

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