TireSizesFinder

265/40R19 vs 225/40R20

225/40R20 is 0.26 in (6.6 mm) shorter than 265/40R19, a −0.95% diameter difference. With the speedometer set for 265/40R19, an indicated 60 mph is 59.4 mph on 225/40R20.

Is this a safe swap?

Diameter difference −0.95%: under 1%

By overall diameter alone, 225/40R20 is a near match for 265/40R19; 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: 265/40R19 (27.35 in) vs 225/40R20 (27.09 in)265/40R1927.35 in × 10.43 in225/40R2027.09 in × 8.86 in
Side profile and tread width, drawn to the same scale.
265/40R19 vs 225/40R20 differences
Measurement265/40R19225/40R20Difference% diff
Overall diameter27.35 in (694.6 mm)27.09 in (688.0 mm)−0.26 in (−6.6 mm)−0.95%
Sidewall height4.17 in (106.0 mm)3.54 in (90.0 mm)−0.63 in (−16.0 mm)−15.09%
Section width10.43 in (265.0 mm)8.86 in (225.0 mm)−1.57 in (−40.0 mm)−15.09%
Circumference85.91 in (2,182.2 mm)85.10 in (2,161.4 mm)−0.82 in (−20.7 mm)−0.95%
Revolutions per mile738745+7+0.96%
True speed with the speedometer calibrated for 265/40R19
IndicatedActual on 265/40R19Actual on 225/40R20Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.4 mph−0.6 mph
75 mph75.0 mph74.3 mph−0.7 mph

Ride-height change: 225/40R20 lowers the vehicle by 0.13 in (3.3 mm) at the axle (half the −6.6 mm diameter difference).

225/40R20 is 0.26 in shorter than 265/40R19 and 40 mm narrower, a 0.95% difference in overall diameter.

With the speedometer calibrated for 265/40R19, an indicated 60 mph is actually 59.4 mph on 225/40R20, and revolutions per mile change from 738 to 745.

225/40R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 265/40R19.

Size pages

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