295/40R20 vs 315/30R22

315/30R22 is 0.15 in (3.8 mm) taller than 295/40R20, a +0.51% diameter difference. With the speedometer set for 295/40R20, an indicated 60 mph is 60.3 mph on 315/30R22.

Is this a safe swap?

Diameter difference +0.51%: under 1%

By overall diameter alone, 315/30R22 is a near match for 295/40R20; 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.

295/40R20 vs 315/30R22 differences
Measurement	295/40R20	315/30R22	Difference	% diff
Overall diameter	29.29 in (744.0 mm)	29.44 in (747.8 mm)	+0.15 in (+3.8 mm)	+0.51%
Sidewall height	4.65 in (118.0 mm)	3.72 in (94.5 mm)	−0.93 in (−23.5 mm)	−19.92%
Section width	11.61 in (295.0 mm)	12.40 in (315.0 mm)	+0.79 in (+20.0 mm)	+6.78%
Circumference	92.02 in (2,337.3 mm)	92.49 in (2,349.3 mm)	+0.47 in (+11.9 mm)	+0.51%
Revolutions per mile	689	685	−3	−0.51%

True speed with the speedometer calibrated for 295/40R20
Indicated	Actual on 295/40R20	Actual on 315/30R22	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 315/30R22 raises the vehicle by 0.07 in (1.9 mm) at the axle (half the +3.8 mm diameter difference).

315/30R22 is 0.15 in taller than 295/40R20 and 20 mm wider, a 0.51% difference in overall diameter.

With the speedometer calibrated for 295/40R20, an indicated 60 mph is actually 60.3 mph on 315/30R22, and revolutions per mile change from 689 to 685.

315/30R22 mounts on a 22-inch wheel, a plus-2 fitment from the 20-inch wheel of 295/40R20.

Size pages

Other comparisons with 295/40R20

Other comparisons with 315/30R22

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