295/40R20 vs 255/35R22

255/35R22 is 0.26 in (6.7 mm) shorter than 295/40R20, a −0.90% diameter difference. With the speedometer set for 295/40R20, an indicated 60 mph is 59.5 mph on 255/35R22.

Is this a safe swap?

Diameter difference −0.90%: under 1%

By overall diameter alone, 255/35R22 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 255/35R22 differences
Measurement	295/40R20	255/35R22	Difference	% diff
Overall diameter	29.29 in (744.0 mm)	29.03 in (737.3 mm)	−0.26 in (−6.7 mm)	−0.90%
Sidewall height	4.65 in (118.0 mm)	3.51 in (89.3 mm)	−1.13 in (−28.7 mm)	−24.36%
Section width	11.61 in (295.0 mm)	10.04 in (255.0 mm)	−1.57 in (−40.0 mm)	−13.56%
Circumference	92.02 in (2,337.3 mm)	91.19 in (2,316.3 mm)	−0.83 in (−21.0 mm)	−0.90%
Revolutions per mile	689	695	+6	+0.91%

True speed with the speedometer calibrated for 295/40R20
Indicated	Actual on 295/40R20	Actual on 255/35R22	Difference
30 mph	30.0 mph	29.7 mph	−0.3 mph
60 mph	60.0 mph	59.5 mph	−0.5 mph
75 mph	75.0 mph	74.3 mph	−0.7 mph

Ride-height change: 255/35R22 lowers the vehicle by 0.13 in (3.4 mm) at the axle (half the −6.7 mm diameter difference).

255/35R22 is 0.26 in shorter than 295/40R20 and 40 mm narrower, a 0.90% difference in overall diameter.

With the speedometer calibrated for 295/40R20, an indicated 60 mph is actually 59.5 mph on 255/35R22, and revolutions per mile change from 689 to 695.

255/35R22 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 255/35R22

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