TireSizesFinder

295/30R21 vs 255/30R22

255/30R22 is 0.06 in (1.4 mm) taller than 295/30R21, a +0.20% diameter difference. With the speedometer set for 295/30R21, an indicated 60 mph is 60.1 mph on 255/30R22.

Is this a safe swap?

Diameter difference +0.20%: under 1%

By overall diameter alone, 255/30R22 is a near match for 295/30R21; 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: 295/30R21 (27.97 in) vs 255/30R22 (28.02 in)295/30R2127.97 in × 11.61 in255/30R2228.02 in × 10.04 in
Side profile and tread width, drawn to the same scale.
295/30R21 vs 255/30R22 differences
Measurement295/30R21255/30R22Difference% diff
Overall diameter27.97 in (710.4 mm)28.02 in (711.8 mm)+0.06 in (+1.4 mm)+0.20%
Sidewall height3.48 in (88.5 mm)3.01 in (76.5 mm)−0.47 in (−12.0 mm)−13.56%
Section width11.61 in (295.0 mm)10.04 in (255.0 mm)−1.57 in (−40.0 mm)−13.56%
Circumference87.87 in (2,231.8 mm)88.04 in (2,236.2 mm)+0.17 in (+4.4 mm)+0.20%
Revolutions per mile721720−1−0.20%
True speed with the speedometer calibrated for 295/30R21
IndicatedActual on 295/30R21Actual on 255/30R22Difference
30 mph30.0 mph30.1 mph+0.1 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 255/30R22 raises the vehicle by 0.03 in (0.7 mm) at the axle (half the +1.4 mm diameter difference).

255/30R22 is 0.06 in taller than 295/30R21 and 40 mm narrower, a 0.20% difference in overall diameter.

With the speedometer calibrated for 295/30R21, an indicated 60 mph is actually 60.1 mph on 255/30R22, and revolutions per mile change from 721 to 720.

255/30R22 mounts on a 22-inch wheel, a plus-1 fitment from the 21-inch wheel of 295/30R21.

Size pages

Other comparisons with 295/30R21

Other comparisons with 255/30R22

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