325/30R21 vs 265/30R22

265/30R22 is 0.42 in (10.6 mm) shorter than 325/30R21, a −1.46% diameter difference. With the speedometer set for 325/30R21, an indicated 60 mph is 59.1 mph on 265/30R22.

Is this a safe swap?

Diameter difference −1.46%: within the ±3% guideline

By overall diameter alone, 265/30R22 falls inside the ±3% range commonly used as a guideline when replacing 325/30R21. 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.

325/30R21 vs 265/30R22 differences
Measurement	325/30R21	265/30R22	Difference	% diff
Overall diameter	28.68 in (728.4 mm)	28.26 in (717.8 mm)	−0.42 in (−10.6 mm)	−1.46%
Sidewall height	3.84 in (97.5 mm)	3.13 in (79.5 mm)	−0.71 in (−18.0 mm)	−18.46%
Section width	12.80 in (325.0 mm)	10.43 in (265.0 mm)	−2.36 in (−60.0 mm)	−18.46%
Circumference	90.09 in (2,288.3 mm)	88.78 in (2,255.0 mm)	−1.31 in (−33.3 mm)	−1.46%
Revolutions per mile	703	714	+10	+1.48%

True speed with the speedometer calibrated for 325/30R21
Indicated	Actual on 325/30R21	Actual on 265/30R22	Difference
30 mph	30.0 mph	29.6 mph	−0.4 mph
60 mph	60.0 mph	59.1 mph	−0.9 mph
75 mph	75.0 mph	73.9 mph	−1.1 mph

Ride-height change: 265/30R22 lowers the vehicle by 0.21 in (5.3 mm) at the axle (half the −10.6 mm diameter difference).

265/30R22 is 0.42 in shorter than 325/30R21 and 60 mm narrower, a 1.46% difference in overall diameter.

With the speedometer calibrated for 325/30R21, an indicated 60 mph is actually 59.1 mph on 265/30R22, and revolutions per mile change from 703 to 714.

265/30R22 mounts on a 22-inch wheel, a plus-1 fitment from the 21-inch wheel of 325/30R21.

Size pages

Other comparisons with 325/30R21

Other comparisons with 265/30R22

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