TireSizesFinder

215/50R18 vs 235/40R19

235/40R19 is 0.06 in (1.6 mm) shorter than 215/50R18, a −0.24% diameter difference. With the speedometer set for 215/50R18, an indicated 60 mph is 59.9 mph on 235/40R19.

Is this a safe swap?

Diameter difference −0.24%: under 1%

By overall diameter alone, 235/40R19 is a near match for 215/50R18; 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: 215/50R18 (26.46 in) vs 235/40R19 (26.40 in)215/50R1826.46 in × 8.46 in235/40R1926.40 in × 9.25 in
Side profile and tread width, drawn to the same scale.
215/50R18 vs 235/40R19 differences
Measurement215/50R18235/40R19Difference% diff
Overall diameter26.46 in (672.2 mm)26.40 in (670.6 mm)−0.06 in (−1.6 mm)−0.24%
Sidewall height4.23 in (107.5 mm)3.70 in (94.0 mm)−0.53 in (−13.5 mm)−12.56%
Section width8.46 in (215.0 mm)9.25 in (235.0 mm)+0.79 in (+20.0 mm)+9.30%
Circumference83.14 in (2,111.8 mm)82.94 in (2,106.8 mm)−0.20 in (−5.0 mm)−0.24%
Revolutions per mile762764+2+0.24%
True speed with the speedometer calibrated for 215/50R18
IndicatedActual on 215/50R18Actual on 235/40R19Difference
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: 235/40R19 lowers the vehicle by 0.03 in (0.8 mm) at the axle (half the −1.6 mm diameter difference).

235/40R19 is 0.06 in shorter than 215/50R18 and 20 mm wider, a 0.24% difference in overall diameter.

With the speedometer calibrated for 215/50R18, an indicated 60 mph is actually 59.9 mph on 235/40R19, and revolutions per mile change from 762 to 764.

235/40R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 215/50R18.

Size pages

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