295/35R18 vs 225/40R19

225/40R19 is 0.04 in (1.1 mm) shorter than 295/35R18, a −0.17% diameter difference. With the speedometer set for 295/35R18, an indicated 60 mph is 59.9 mph on 225/40R19.

Is this a safe swap?

Diameter difference −0.17%: under 1%

By overall diameter alone, 225/40R19 is a near match for 295/35R18; 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.

295/35R18 vs 225/40R19 differences
Measurement	295/35R18	225/40R19	Difference	% diff
Overall diameter	26.13 in (663.7 mm)	26.09 in (662.6 mm)	−0.04 in (−1.1 mm)	−0.17%
Sidewall height	4.06 in (103.3 mm)	3.54 in (90.0 mm)	−0.52 in (−13.2 mm)	−12.83%
Section width	11.61 in (295.0 mm)	8.86 in (225.0 mm)	−2.76 in (−70.0 mm)	−23.73%
Circumference	82.09 in (2,085.1 mm)	81.95 in (2,081.6 mm)	−0.14 in (−3.5 mm)	−0.17%
Revolutions per mile	772	773	+1	+0.17%

True speed with the speedometer calibrated for 295/35R18
Indicated	Actual on 295/35R18	Actual on 225/40R19	Difference
30 mph	30.0 mph	30.0 mph	0.0 mph
60 mph	60.0 mph	59.9 mph	−0.1 mph
75 mph	75.0 mph	74.9 mph	−0.1 mph

Ride-height change: 225/40R19 lowers the vehicle by 0.02 in (0.6 mm) at the axle (half the −1.1 mm diameter difference).

225/40R19 is 0.04 in shorter than 295/35R18 and 70 mm narrower, a 0.17% difference in overall diameter.

With the speedometer calibrated for 295/35R18, an indicated 60 mph is actually 59.9 mph on 225/40R19, and revolutions per mile change from 772 to 773.

225/40R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 295/35R18.

Size pages

Other comparisons with 295/35R18

Other comparisons with 225/40R19

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