275/40R20 vs 265/30R22

265/30R22 is 0.40 in (10.2 mm) shorter than 275/40R20, a −1.40% diameter difference. With the speedometer set for 275/40R20, an indicated 60 mph is 59.2 mph on 265/30R22.

Is this a safe swap?

Diameter difference −1.40%: within the ±3% guideline

By overall diameter alone, 265/30R22 falls inside the ±3% range commonly used as a guideline when replacing 275/40R20. 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.

275/40R20 vs 265/30R22 differences
Measurement	275/40R20	265/30R22	Difference	% diff
Overall diameter	28.66 in (728.0 mm)	28.26 in (717.8 mm)	−0.40 in (−10.2 mm)	−1.40%
Sidewall height	4.33 in (110.0 mm)	3.13 in (79.5 mm)	−1.20 in (−30.5 mm)	−27.73%
Section width	10.83 in (275.0 mm)	10.43 in (265.0 mm)	−0.39 in (−10.0 mm)	−3.64%
Circumference	90.04 in (2,287.1 mm)	88.78 in (2,255.0 mm)	−1.26 in (−32.0 mm)	−1.40%
Revolutions per mile	704	714	+10	+1.42%

True speed with the speedometer calibrated for 275/40R20
Indicated	Actual on 275/40R20	Actual on 265/30R22	Difference
30 mph	30.0 mph	29.6 mph	−0.4 mph
60 mph	60.0 mph	59.2 mph	−0.8 mph
75 mph	75.0 mph	73.9 mph	−1.1 mph

Ride-height change: 265/30R22 lowers the vehicle by 0.20 in (5.1 mm) at the axle (half the −10.2 mm diameter difference).

265/30R22 is 0.40 in shorter than 275/40R20 and 10 mm narrower, a 1.40% difference in overall diameter.

With the speedometer calibrated for 275/40R20, an indicated 60 mph is actually 59.2 mph on 265/30R22, and revolutions per mile change from 704 to 714.

265/30R22 mounts on a 22-inch wheel, a plus-2 fitment from the 20-inch wheel of 275/40R20.

Size pages

Other comparisons with 275/40R20

Other comparisons with 265/30R22

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