305/35R22 vs 285/30R24

285/30R24 is 0.33 in (8.3 mm) taller than 305/35R22, a +1.07% diameter difference. With the speedometer set for 305/35R22, an indicated 60 mph is 60.6 mph on 285/30R24.

Is this a safe swap?

Diameter difference +1.07%: within the ±3% guideline

By overall diameter alone, 285/30R24 falls inside the ±3% range commonly used as a guideline when replacing 305/35R22. 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.

305/35R22 vs 285/30R24 differences
Measurement	305/35R22	285/30R24	Difference	% diff
Overall diameter	30.41 in (772.3 mm)	30.73 in (780.6 mm)	+0.33 in (+8.3 mm)	+1.07%
Sidewall height	4.20 in (106.8 mm)	3.37 in (85.5 mm)	−0.84 in (−21.2 mm)	−19.91%
Section width	12.01 in (305.0 mm)	11.22 in (285.0 mm)	−0.79 in (−20.0 mm)	−6.56%
Circumference	95.52 in (2,426.3 mm)	96.55 in (2,452.3 mm)	+1.03 in (+26.1 mm)	+1.07%
Revolutions per mile	663	656	−7	−1.06%

True speed with the speedometer calibrated for 305/35R22
Indicated	Actual on 305/35R22	Actual on 285/30R24	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.6 mph	+0.6 mph
75 mph	75.0 mph	75.8 mph	+0.8 mph

Ride-height change: 285/30R24 raises the vehicle by 0.16 in (4.1 mm) at the axle (half the +8.3 mm diameter difference).

285/30R24 is 0.33 in taller than 305/35R22 and 20 mm narrower, a 1.07% difference in overall diameter.

With the speedometer calibrated for 305/35R22, an indicated 60 mph is actually 60.6 mph on 285/30R24, and revolutions per mile change from 663 to 656.

285/30R24 mounts on a 24-inch wheel, a plus-2 fitment from the 22-inch wheel of 305/35R22.

Size pages

Other comparisons with 305/35R22

Other comparisons with 285/30R24

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