TireSizesFinder

275/50R19 vs 245/50R20

245/50R20 is 0.18 in (4.6 mm) shorter than 275/50R19, a −0.61% diameter difference. With the speedometer set for 275/50R19, an indicated 60 mph is 59.6 mph on 245/50R20.

Is this a safe swap?

Diameter difference −0.61%: under 1%

By overall diameter alone, 245/50R20 is a near match for 275/50R19; 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: 275/50R19 (29.83 in) vs 245/50R20 (29.65 in)275/50R1929.83 in × 10.83 in245/50R2029.65 in × 9.65 in
Side profile and tread width, drawn to the same scale.
275/50R19 vs 245/50R20 differences
Measurement275/50R19245/50R20Difference% diff
Overall diameter29.83 in (757.6 mm)29.65 in (753.0 mm)−0.18 in (−4.6 mm)−0.61%
Sidewall height5.41 in (137.5 mm)4.82 in (122.5 mm)−0.59 in (−15.0 mm)−10.91%
Section width10.83 in (275.0 mm)9.65 in (245.0 mm)−1.18 in (−30.0 mm)−10.91%
Circumference93.70 in (2,380.1 mm)93.13 in (2,365.6 mm)−0.57 in (−14.5 mm)−0.61%
Revolutions per mile676680+4+0.61%
True speed with the speedometer calibrated for 275/50R19
IndicatedActual on 275/50R19Actual on 245/50R20Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.6 mph−0.4 mph
75 mph75.0 mph74.5 mph−0.5 mph

Ride-height change: 245/50R20 lowers the vehicle by 0.09 in (2.3 mm) at the axle (half the −4.6 mm diameter difference).

245/50R20 is 0.18 in shorter than 275/50R19 and 30 mm narrower, a 0.61% difference in overall diameter.

With the speedometer calibrated for 275/50R19, an indicated 60 mph is actually 59.6 mph on 245/50R20, and revolutions per mile change from 676 to 680.

245/50R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 275/50R19.

Size pages

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