265/45R20 vs 315/30R22

315/30R22 is 0.05 in (1.3 mm) taller than 265/45R20, a +0.17% diameter difference. With the speedometer set for 265/45R20, an indicated 60 mph is 60.1 mph on 315/30R22.

Is this a safe swap?

Diameter difference +0.17%: under 1%

By overall diameter alone, 315/30R22 is a near match for 265/45R20; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

265/45R20 vs 315/30R22 differences
Measurement	265/45R20	315/30R22	Difference	% diff
Overall diameter	29.39 in (746.5 mm)	29.44 in (747.8 mm)	+0.05 in (+1.3 mm)	+0.17%
Sidewall height	4.69 in (119.3 mm)	3.72 in (94.5 mm)	−0.97 in (−24.7 mm)	−20.75%
Section width	10.43 in (265.0 mm)	12.40 in (315.0 mm)	+1.97 in (+50.0 mm)	+18.87%
Circumference	92.33 in (2,345.2 mm)	92.49 in (2,349.3 mm)	+0.16 in (+4.1 mm)	+0.17%
Revolutions per mile	686	685	−1	−0.17%

True speed with the speedometer calibrated for 265/45R20
Indicated	Actual on 265/45R20	Actual on 315/30R22	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.1 mph	+0.1 mph
75 mph	75.0 mph	75.1 mph	+0.1 mph

Ride-height change: 315/30R22 raises the vehicle by 0.03 in (0.6 mm) at the axle (half the +1.3 mm diameter difference).

315/30R22 is 0.05 in taller than 265/45R20 and 50 mm wider, a 0.17% difference in overall diameter.

With the speedometer calibrated for 265/45R20, an indicated 60 mph is actually 60.1 mph on 315/30R22, and revolutions per mile change from 686 to 685.

315/30R22 mounts on a 22-inch wheel, a plus-2 fitment from the 20-inch wheel of 265/45R20.

Size pages

Other comparisons with 265/45R20

Other comparisons with 315/30R22

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.