TireSizesFinder

255/45R21 vs 285/35R22

285/35R22 is 0.18 in (4.6 mm) shorter than 255/45R21, a −0.60% diameter difference. With the speedometer set for 255/45R21, an indicated 60 mph is 59.6 mph on 285/35R22.

Is this a safe swap?

Diameter difference −0.60%: under 1%

By overall diameter alone, 285/35R22 is a near match for 255/45R21; 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: 255/45R21 (30.04 in) vs 285/35R22 (29.85 in)255/45R2130.04 in × 10.04 in285/35R2229.85 in × 11.22 in
Side profile and tread width, drawn to the same scale.
255/45R21 vs 285/35R22 differences
Measurement255/45R21285/35R22Difference% diff
Overall diameter30.04 in (762.9 mm)29.85 in (758.3 mm)−0.18 in (−4.6 mm)−0.60%
Sidewall height4.52 in (114.8 mm)3.93 in (99.8 mm)−0.59 in (−15.0 mm)−13.07%
Section width10.04 in (255.0 mm)11.22 in (285.0 mm)+1.18 in (+30.0 mm)+11.76%
Circumference94.36 in (2,396.7 mm)93.79 in (2,382.3 mm)−0.57 in (−14.5 mm)−0.60%
Revolutions per mile671676+4+0.61%
True speed with the speedometer calibrated for 255/45R21
IndicatedActual on 255/45R21Actual on 285/35R22Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.6 mph−0.4 mph
75 mph75.0 mph74.5 mph−0.5 mph

Ride-height change: 285/35R22 lowers the vehicle by 0.09 in (2.3 mm) at the axle (half the −4.6 mm diameter difference).

285/35R22 is 0.18 in shorter than 255/45R21 and 30 mm wider, a 0.60% difference in overall diameter.

With the speedometer calibrated for 255/45R21, an indicated 60 mph is actually 59.6 mph on 285/35R22, and revolutions per mile change from 671 to 676.

285/35R22 mounts on a 22-inch wheel, a plus-1 fitment from the 21-inch wheel of 255/45R21.

Size pages

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