TireSizesFinder

275/35R19 vs 245/35R20

245/35R20 is 0.17 in (4.4 mm) taller than 275/35R19, a +0.65% diameter difference. With the speedometer set for 275/35R19, an indicated 60 mph is 60.4 mph on 245/35R20.

Is this a safe swap?

Diameter difference +0.65%: under 1%

By overall diameter alone, 245/35R20 is a near match for 275/35R19; 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: 275/35R19 (26.58 in) vs 245/35R20 (26.75 in)275/35R1926.58 in × 10.83 in245/35R2026.75 in × 9.65 in
Side profile and tread width, drawn to the same scale.
275/35R19 vs 245/35R20 differences
Measurement275/35R19245/35R20Difference% diff
Overall diameter26.58 in (675.1 mm)26.75 in (679.5 mm)+0.17 in (+4.4 mm)+0.65%
Sidewall height3.79 in (96.3 mm)3.38 in (85.8 mm)−0.41 in (−10.5 mm)−10.91%
Section width10.83 in (275.0 mm)9.65 in (245.0 mm)−1.18 in (−30.0 mm)−10.91%
Circumference83.50 in (2,120.9 mm)84.04 in (2,134.7 mm)+0.54 in (+13.8 mm)+0.65%
Revolutions per mile759754−5−0.65%
True speed with the speedometer calibrated for 275/35R19
IndicatedActual on 275/35R19Actual on 245/35R20Difference
30 mph30.0 mph30.2 mph+0.2 mph
60 mph60.0 mph60.4 mph+0.4 mph
75 mph75.0 mph75.5 mph+0.5 mph

Ride-height change: 245/35R20 raises the vehicle by 0.09 in (2.2 mm) at the axle (half the +4.4 mm diameter difference).

245/35R20 is 0.17 in taller than 275/35R19 and 30 mm narrower, a 0.65% difference in overall diameter.

With the speedometer calibrated for 275/35R19, an indicated 60 mph is actually 60.4 mph on 245/35R20, and revolutions per mile change from 759 to 754.

245/35R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 275/35R19.

Size pages

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