225/45R17 vs 245/30R19

245/30R19 is 0.19 in (4.7 mm) shorter than 225/45R17, a −0.74% diameter difference. With the speedometer set for 225/45R17, an indicated 60 mph is 59.6 mph on 245/30R19.

Is this a safe swap?

Diameter difference −0.74%: under 1%

By overall diameter alone, 245/30R19 is a near match for 225/45R17; 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.

225/45R17 vs 245/30R19 differences
Measurement	225/45R17	245/30R19	Difference	% diff
Overall diameter	24.97 in (634.3 mm)	24.79 in (629.6 mm)	−0.19 in (−4.7 mm)	−0.74%
Sidewall height	3.99 in (101.3 mm)	2.89 in (73.5 mm)	−1.09 in (−27.7 mm)	−27.41%
Section width	8.86 in (225.0 mm)	9.65 in (245.0 mm)	+0.79 in (+20.0 mm)	+8.89%
Circumference	78.45 in (1,992.7 mm)	77.87 in (1,977.9 mm)	−0.58 in (−14.8 mm)	−0.74%
Revolutions per mile	808	814	+6	+0.75%

True speed with the speedometer calibrated for 225/45R17
Indicated	Actual on 225/45R17	Actual on 245/30R19	Difference
30 mph	30.0 mph	29.8 mph	−0.2 mph
60 mph	60.0 mph	59.6 mph	−0.4 mph
75 mph	75.0 mph	74.4 mph	−0.6 mph

Ride-height change: 245/30R19 lowers the vehicle by 0.09 in (2.4 mm) at the axle (half the −4.7 mm diameter difference).

245/30R19 is 0.19 in shorter than 225/45R17 and 20 mm wider, a 0.74% difference in overall diameter.

With the speedometer calibrated for 225/45R17, an indicated 60 mph is actually 59.6 mph on 245/30R19, and revolutions per mile change from 808 to 814.

245/30R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 225/45R17.

Size pages

Other comparisons with 225/45R17

Other comparisons with 245/30R19

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