TireSizesFinder

295/40R19 vs 235/45R20

235/45R20 is 0.04 in (0.9 mm) taller than 295/40R19, a +0.13% diameter difference. With the speedometer set for 295/40R19, an indicated 60 mph is 60.1 mph on 235/45R20.

Is this a safe swap?

Diameter difference +0.13%: under 1%

By overall diameter alone, 235/45R20 is a near match for 295/40R19; 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: 295/40R19 (28.29 in) vs 235/45R20 (28.33 in)295/40R1928.29 in × 11.61 in235/45R2028.33 in × 9.25 in
Side profile and tread width, drawn to the same scale.
295/40R19 vs 235/45R20 differences
Measurement295/40R19235/45R20Difference% diff
Overall diameter28.29 in (718.6 mm)28.33 in (719.5 mm)+0.04 in (+0.9 mm)+0.13%
Sidewall height4.65 in (118.0 mm)4.16 in (105.8 mm)−0.48 in (−12.2 mm)−10.38%
Section width11.61 in (295.0 mm)9.25 in (235.0 mm)−2.36 in (−60.0 mm)−20.34%
Circumference88.88 in (2,257.5 mm)88.99 in (2,260.4 mm)+0.11 in (+2.8 mm)+0.13%
Revolutions per mile713712−1−0.13%
True speed with the speedometer calibrated for 295/40R19
IndicatedActual on 295/40R19Actual on 235/45R20Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 235/45R20 raises the vehicle by 0.02 in (0.5 mm) at the axle (half the +0.9 mm diameter difference).

235/45R20 is 0.04 in taller than 295/40R19 and 60 mm narrower, a 0.13% difference in overall diameter.

With the speedometer calibrated for 295/40R19, an indicated 60 mph is actually 60.1 mph on 235/45R20, and revolutions per mile change from 713 to 712.

235/45R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 295/40R19.

Size pages

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