295/35R21 vs 255/35R22

255/35R22 is 0.10 in (2.6 mm) shorter than 295/35R21, a −0.35% diameter difference. With the speedometer set for 295/35R21, an indicated 60 mph is 59.8 mph on 255/35R22.

Is this a safe swap?

Diameter difference −0.35%: under 1%

By overall diameter alone, 255/35R22 is a near match for 295/35R21; 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: 295/35R21 (29.13 in) vs 255/35R22 (29.03 in)295/35R2129.13 in × 11.61 in255/35R2229.03 in × 10.04 in
Side profile and tread width, drawn to the same scale.
295/35R21 vs 255/35R22 differences
Measurement295/35R21255/35R22Difference% diff
Overall diameter29.13 in (739.9 mm)29.03 in (737.3 mm)−0.10 in (−2.6 mm)−0.35%
Sidewall height4.06 in (103.3 mm)3.51 in (89.3 mm)−0.55 in (−14.0 mm)−13.56%
Section width11.61 in (295.0 mm)10.04 in (255.0 mm)−1.57 in (−40.0 mm)−13.56%
Circumference91.51 in (2,324.5 mm)91.19 in (2,316.3 mm)−0.32 in (−8.2 mm)−0.35%
Revolutions per mile692695+2+0.35%
True speed with the speedometer calibrated for 295/35R21
IndicatedActual on 295/35R21Actual on 255/35R22Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.8 mph−0.2 mph
75 mph75.0 mph74.7 mph−0.3 mph

Ride-height change: 255/35R22 lowers the vehicle by 0.05 in (1.3 mm) at the axle (half the −2.6 mm diameter difference).

255/35R22 is 0.10 in shorter than 295/35R21 and 40 mm narrower, a 0.35% difference in overall diameter.

With the speedometer calibrated for 295/35R21, an indicated 60 mph is actually 59.8 mph on 255/35R22, and revolutions per mile change from 692 to 695.

255/35R22 mounts on a 22-inch wheel, a plus-1 fitment from the 21-inch wheel of 295/35R21.

Size pages

Other comparisons with 295/35R21

Other comparisons with 255/35R22

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