265/40R19 vs 305/35R19

305/35R19 is 0.06 in (1.5 mm) taller than 265/40R19, a +0.22% diameter difference. With the speedometer set for 265/40R19, an indicated 60 mph is 60.1 mph on 305/35R19.

Is this a safe swap?

Diameter difference +0.22%: under 1%

By overall diameter alone, 305/35R19 is a near match for 265/40R19; 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.

265/40R19 vs 305/35R19 differences
Measurement	265/40R19	305/35R19	Difference	% diff
Overall diameter	27.35 in (694.6 mm)	27.41 in (696.1 mm)	+0.06 in (+1.5 mm)	+0.22%
Sidewall height	4.17 in (106.0 mm)	4.20 in (106.8 mm)	+0.03 in (+0.8 mm)	+0.71%
Section width	10.43 in (265.0 mm)	12.01 in (305.0 mm)	+1.57 in (+40.0 mm)	+15.09%
Circumference	85.91 in (2,182.2 mm)	86.10 in (2,186.9 mm)	+0.19 in (+4.7 mm)	+0.22%
Revolutions per mile	738	736	−2	−0.22%

True speed with the speedometer calibrated for 265/40R19
Indicated	Actual on 265/40R19	Actual on 305/35R19	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.1 mph	+0.1 mph
75 mph	75.0 mph	75.2 mph	+0.2 mph

Ride-height change: 305/35R19 raises the vehicle by 0.03 in (0.8 mm) at the axle (half the +1.5 mm diameter difference).

305/35R19 is 0.06 in taller than 265/40R19 and 40 mm wider, a 0.22% difference in overall diameter.

With the speedometer calibrated for 265/40R19, an indicated 60 mph is actually 60.1 mph on 305/35R19, and revolutions per mile change from 738 to 736.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 265/40R19

Other comparisons with 305/35R19

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