265/40R18 vs 275/35R19

275/35R19 is 0.23 in (5.9 mm) taller than 265/40R18, a +0.88% diameter difference. With the speedometer set for 265/40R18, an indicated 60 mph is 60.5 mph on 275/35R19.

Is this a safe swap?

Diameter difference +0.88%: under 1%

By overall diameter alone, 275/35R19 is a near match for 265/40R18; 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.

265/40R18 vs 275/35R19 differences
Measurement	265/40R18	275/35R19	Difference	% diff
Overall diameter	26.35 in (669.2 mm)	26.58 in (675.1 mm)	+0.23 in (+5.9 mm)	+0.88%
Sidewall height	4.17 in (106.0 mm)	3.79 in (96.3 mm)	−0.38 in (−9.7 mm)	−9.20%
Section width	10.43 in (265.0 mm)	10.83 in (275.0 mm)	+0.39 in (+10.0 mm)	+3.77%
Circumference	82.77 in (2,102.4 mm)	83.50 in (2,120.9 mm)	+0.73 in (+18.5 mm)	+0.88%
Revolutions per mile	765	759	−7	−0.87%

True speed with the speedometer calibrated for 265/40R18
Indicated	Actual on 265/40R18	Actual on 275/35R19	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.5 mph	+0.5 mph
75 mph	75.0 mph	75.7 mph	+0.7 mph

Ride-height change: 275/35R19 raises the vehicle by 0.12 in (2.9 mm) at the axle (half the +5.9 mm diameter difference).

275/35R19 is 0.23 in taller than 265/40R18 and 10 mm wider, a 0.88% difference in overall diameter.

With the speedometer calibrated for 265/40R18, an indicated 60 mph is actually 60.5 mph on 275/35R19, and revolutions per mile change from 765 to 759.

275/35R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 265/40R18.

Size pages

Other comparisons with 265/40R18

Other comparisons with 275/35R19

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