275/45R22 vs 305/30R24

305/30R24 is 0.54 in (13.7 mm) shorter than 275/45R22, a −1.70% diameter difference. With the speedometer set for 275/45R22, an indicated 60 mph is 59.0 mph on 305/30R24.

Is this a safe swap?

Diameter difference −1.70%: within the ±3% guideline

By overall diameter alone, 305/30R24 falls inside the ±3% range commonly used as a guideline when replacing 275/45R22. 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.

275/45R22 vs 305/30R24 differences
Measurement	275/45R22	305/30R24	Difference	% diff
Overall diameter	31.74 in (806.3 mm)	31.20 in (792.6 mm)	−0.54 in (−13.7 mm)	−1.70%
Sidewall height	4.87 in (123.8 mm)	3.60 in (91.5 mm)	−1.27 in (−32.2 mm)	−26.06%
Section width	10.83 in (275.0 mm)	12.01 in (305.0 mm)	+1.18 in (+30.0 mm)	+10.91%
Circumference	99.73 in (2,533.1 mm)	98.03 in (2,490.0 mm)	−1.69 in (−43.0 mm)	−1.70%
Revolutions per mile	635	646	+11	+1.73%

True speed with the speedometer calibrated for 275/45R22
Indicated	Actual on 275/45R22	Actual on 305/30R24	Difference
30 mph	30.0 mph	29.5 mph	−0.5 mph
60 mph	60.0 mph	59.0 mph	−1.0 mph
75 mph	75.0 mph	73.7 mph	−1.3 mph

Ride-height change: 305/30R24 lowers the vehicle by 0.27 in (6.9 mm) at the axle (half the −13.7 mm diameter difference).

305/30R24 is 0.54 in shorter than 275/45R22 and 30 mm wider, a 1.70% difference in overall diameter.

With the speedometer calibrated for 275/45R22, an indicated 60 mph is actually 59.0 mph on 305/30R24, and revolutions per mile change from 635 to 646.

305/30R24 mounts on a 24-inch wheel, a plus-2 fitment from the 22-inch wheel of 275/45R22.

Size pages

Other comparisons with 275/45R22

Other comparisons with 305/30R24

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