285/35R21 vs 245/35R22

245/35R22 is 0.10 in (2.6 mm) shorter than 285/35R21, a −0.35% diameter difference. With the speedometer set for 285/35R21, an indicated 60 mph is 59.8 mph on 245/35R22.

Is this a safe swap?

Diameter difference −0.35%: under 1%

By overall diameter alone, 245/35R22 is a near match for 285/35R21; 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: 285/35R21 (28.85 in) vs 245/35R22 (28.75 in)285/35R2128.85 in × 11.22 in245/35R2228.75 in × 9.65 in
Side profile and tread width, drawn to the same scale.
285/35R21 vs 245/35R22 differences
Measurement285/35R21245/35R22Difference% diff
Overall diameter28.85 in (732.9 mm)28.75 in (730.3 mm)−0.10 in (−2.6 mm)−0.35%
Sidewall height3.93 in (99.8 mm)3.38 in (85.8 mm)−0.55 in (−14.0 mm)−14.04%
Section width11.22 in (285.0 mm)9.65 in (245.0 mm)−1.57 in (−40.0 mm)−14.04%
Circumference90.65 in (2,302.5 mm)90.33 in (2,294.3 mm)−0.32 in (−8.2 mm)−0.35%
Revolutions per mile699701+2+0.36%
True speed with the speedometer calibrated for 285/35R21
IndicatedActual on 285/35R21Actual on 245/35R22Difference
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: 245/35R22 lowers the vehicle by 0.05 in (1.3 mm) at the axle (half the −2.6 mm diameter difference).

245/35R22 is 0.10 in shorter than 285/35R21 and 40 mm narrower, a 0.35% difference in overall diameter.

With the speedometer calibrated for 285/35R21, an indicated 60 mph is actually 59.8 mph on 245/35R22, and revolutions per mile change from 699 to 701.

245/35R22 mounts on a 22-inch wheel, a plus-1 fitment from the 21-inch wheel of 285/35R21.

Size pages

Other comparisons with 285/35R21

Other comparisons with 245/35R22

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