255/40R19 vs 265/40R19

265/40R19 is 0.31 in (8.0 mm) taller than 255/40R19, a +1.17% diameter difference. With the speedometer set for 255/40R19, an indicated 60 mph is 60.7 mph on 265/40R19.

Is this a safe swap?

Diameter difference +1.17%: within the ±3% guideline

By overall diameter alone, 265/40R19 falls inside the ±3% range commonly used as a guideline when replacing 255/40R19. 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.

255/40R19 vs 265/40R19 differences
Measurement	255/40R19	265/40R19	Difference	% diff
Overall diameter	27.03 in (686.6 mm)	27.35 in (694.6 mm)	+0.31 in (+8.0 mm)	+1.17%
Sidewall height	4.02 in (102.0 mm)	4.17 in (106.0 mm)	+0.16 in (+4.0 mm)	+3.92%
Section width	10.04 in (255.0 mm)	10.43 in (265.0 mm)	+0.39 in (+10.0 mm)	+3.92%
Circumference	84.92 in (2,157.0 mm)	85.91 in (2,182.2 mm)	+0.99 in (+25.1 mm)	+1.17%
Revolutions per mile	746	738	−9	−1.15%

True speed with the speedometer calibrated for 255/40R19
Indicated	Actual on 255/40R19	Actual on 265/40R19	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.7 mph	+0.7 mph
75 mph	75.0 mph	75.9 mph	+0.9 mph

Ride-height change: 265/40R19 raises the vehicle by 0.16 in (4.0 mm) at the axle (half the +8.0 mm diameter difference).

265/40R19 is 0.31 in taller than 255/40R19 and 10 mm wider, a 1.17% difference in overall diameter.

With the speedometer calibrated for 255/40R19, an indicated 60 mph is actually 60.7 mph on 265/40R19, and revolutions per mile change from 746 to 738.

Both sizes mount on 19-inch wheels.

Size pages

Other comparisons with 255/40R19

Other comparisons with 265/40R19

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