255/45R20 vs 295/30R22

295/30R22 is 0.07 in (1.7 mm) shorter than 255/45R20, a −0.23% diameter difference. With the speedometer set for 255/45R20, an indicated 60 mph is 59.9 mph on 295/30R22.

Is this a safe swap?

Diameter difference −0.23%: under 1%

By overall diameter alone, 295/30R22 is a near match for 255/45R20; 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.

255/45R20 vs 295/30R22 differences
Measurement	255/45R20	295/30R22	Difference	% diff
Overall diameter	29.04 in (737.5 mm)	28.97 in (735.8 mm)	−0.07 in (−1.7 mm)	−0.23%
Sidewall height	4.52 in (114.8 mm)	3.48 in (88.5 mm)	−1.03 in (−26.2 mm)	−22.88%
Section width	10.04 in (255.0 mm)	11.61 in (295.0 mm)	+1.57 in (+40.0 mm)	+15.69%
Circumference	91.22 in (2,316.9 mm)	91.01 in (2,311.6 mm)	−0.21 in (−5.3 mm)	−0.23%
Revolutions per mile	695	696	+2	+0.23%

True speed with the speedometer calibrated for 255/45R20
Indicated	Actual on 255/45R20	Actual on 295/30R22	Difference
30 mph	30.0 mph	29.9 mph	−0.1 mph
60 mph	60.0 mph	59.9 mph	−0.1 mph
75 mph	75.0 mph	74.8 mph	−0.2 mph

Ride-height change: 295/30R22 lowers the vehicle by 0.03 in (0.9 mm) at the axle (half the −1.7 mm diameter difference).

295/30R22 is 0.07 in shorter than 255/45R20 and 40 mm wider, a 0.23% difference in overall diameter.

With the speedometer calibrated for 255/45R20, an indicated 60 mph is actually 59.9 mph on 295/30R22, and revolutions per mile change from 695 to 696.

295/30R22 mounts on a 22-inch wheel, a plus-2 fitment from the 20-inch wheel of 255/45R20.

Size pages

Other comparisons with 255/45R20

Other comparisons with 295/30R22

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