305/30R19 vs 265/35R19

265/35R19 is 0.10 in (2.5 mm) taller than 305/30R19, a +0.38% diameter difference. With the speedometer set for 305/30R19, an indicated 60 mph is 60.2 mph on 265/35R19.

Is this a safe swap?

Diameter difference +0.38%: under 1%

By overall diameter alone, 265/35R19 is a near match for 305/30R19; 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.

305/30R19 vs 265/35R19 differences
Measurement	305/30R19	265/35R19	Difference	% diff
Overall diameter	26.20 in (665.6 mm)	26.30 in (668.1 mm)	+0.10 in (+2.5 mm)	+0.38%
Sidewall height	3.60 in (91.5 mm)	3.65 in (92.8 mm)	+0.05 in (+1.3 mm)	+1.37%
Section width	12.01 in (305.0 mm)	10.43 in (265.0 mm)	−1.57 in (−40.0 mm)	−13.11%
Circumference	82.32 in (2,091.0 mm)	82.63 in (2,098.9 mm)	+0.31 in (+7.9 mm)	+0.38%
Revolutions per mile	770	767	−3	−0.37%

True speed with the speedometer calibrated for 305/30R19
Indicated	Actual on 305/30R19	Actual on 265/35R19	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.2 mph	+0.2 mph
75 mph	75.0 mph	75.3 mph	+0.3 mph

Ride-height change: 265/35R19 raises the vehicle by 0.05 in (1.3 mm) at the axle (half the +2.5 mm diameter difference).

265/35R19 is 0.10 in taller than 305/30R19 and 40 mm narrower, a 0.38% difference in overall diameter.

With the speedometer calibrated for 305/30R19, an indicated 60 mph is actually 60.2 mph on 265/35R19, and revolutions per mile change from 770 to 767.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 305/30R19

Other comparisons with 265/35R19

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