TireSizesFinder

245/55R20 vs 305/35R22

305/35R22 is 0.20 in (5.2 mm) shorter than 245/55R20, a −0.67% diameter difference. With the speedometer set for 245/55R20, an indicated 60 mph is 59.6 mph on 305/35R22.

Is this a safe swap?

Diameter difference −0.67%: under 1%

By overall diameter alone, 305/35R22 is a near match for 245/55R20; 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: 245/55R20 (30.61 in) vs 305/35R22 (30.41 in)245/55R2030.61 in × 9.65 in305/35R2230.41 in × 12.01 in
Side profile and tread width, drawn to the same scale.
245/55R20 vs 305/35R22 differences
Measurement245/55R20305/35R22Difference% diff
Overall diameter30.61 in (777.5 mm)30.41 in (772.3 mm)−0.20 in (−5.2 mm)−0.67%
Sidewall height5.31 in (134.8 mm)4.20 in (106.8 mm)−1.10 in (−28.0 mm)−20.78%
Section width9.65 in (245.0 mm)12.01 in (305.0 mm)+2.36 in (+60.0 mm)+24.49%
Circumference96.16 in (2,442.6 mm)95.52 in (2,426.3 mm)−0.64 in (−16.3 mm)−0.67%
Revolutions per mile659663+4+0.67%
True speed with the speedometer calibrated for 245/55R20
IndicatedActual on 245/55R20Actual on 305/35R22Difference
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: 305/35R22 lowers the vehicle by 0.10 in (2.6 mm) at the axle (half the −5.2 mm diameter difference).

305/35R22 is 0.20 in shorter than 245/55R20 and 60 mm wider, a 0.67% difference in overall diameter.

With the speedometer calibrated for 245/55R20, an indicated 60 mph is actually 59.6 mph on 305/35R22, and revolutions per mile change from 659 to 663.

305/35R22 mounts on a 22-inch wheel, a plus-2 fitment from the 20-inch wheel of 245/55R20.

Size pages

Other comparisons with 245/55R20

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