255/35R21 vs 265/30R22

265/30R22 is 0.23 in (5.9 mm) taller than 255/35R21, a +0.83% diameter difference. With the speedometer set for 255/35R21, an indicated 60 mph is 60.5 mph on 265/30R22.

Is this a safe swap?

Diameter difference +0.83%: under 1%

By overall diameter alone, 265/30R22 is a near match for 255/35R21; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

255/35R21 vs 265/30R22 differences
Measurement	255/35R21	265/30R22	Difference	% diff
Overall diameter	28.03 in (711.9 mm)	28.26 in (717.8 mm)	+0.23 in (+5.9 mm)	+0.83%
Sidewall height	3.51 in (89.3 mm)	3.13 in (79.5 mm)	−0.38 in (−9.7 mm)	−10.92%
Section width	10.04 in (255.0 mm)	10.43 in (265.0 mm)	+0.39 in (+10.0 mm)	+3.92%
Circumference	88.05 in (2,236.5 mm)	88.78 in (2,255.0 mm)	+0.73 in (+18.5 mm)	+0.83%
Revolutions per mile	720	714	−6	−0.82%

True speed with the speedometer calibrated for 255/35R21
Indicated	Actual on 255/35R21	Actual on 265/30R22	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.5 mph	+0.5 mph
75 mph	75.0 mph	75.6 mph	+0.6 mph

Ride-height change: 265/30R22 raises the vehicle by 0.12 in (2.9 mm) at the axle (half the +5.9 mm diameter difference).

265/30R22 is 0.23 in taller than 255/35R21 and 10 mm wider, a 0.83% difference in overall diameter.

With the speedometer calibrated for 255/35R21, an indicated 60 mph is actually 60.5 mph on 265/30R22, and revolutions per mile change from 720 to 714.

265/30R22 mounts on a 22-inch wheel, a plus-1 fitment from the 21-inch wheel of 255/35R21.

Size pages

Other comparisons with 255/35R21

Other comparisons with 265/30R22

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