255/70R15 vs 265/70R15

265/70R15 is 0.55 in (14.0 mm) taller than 255/70R15, a +1.90% diameter difference. With the speedometer set for 255/70R15, an indicated 60 mph is 61.1 mph on 265/70R15.

Is this a safe swap?

Diameter difference +1.90%: within the ±3% guideline

By overall diameter alone, 265/70R15 falls inside the ±3% range commonly used as a guideline when replacing 255/70R15. 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.

255/70R15 vs 265/70R15 differences
Measurement	255/70R15	265/70R15	Difference	% diff
Overall diameter	29.06 in (738.0 mm)	29.61 in (752.0 mm)	+0.55 in (+14.0 mm)	+1.90%
Sidewall height	7.03 in (178.5 mm)	7.30 in (185.5 mm)	+0.28 in (+7.0 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	91.28 in (2,318.5 mm)	93.01 in (2,362.5 mm)	+1.73 in (+44.0 mm)	+1.90%
Revolutions per mile	694	681	−13	−1.86%

True speed with the speedometer calibrated for 255/70R15
Indicated	Actual on 255/70R15	Actual on 265/70R15	Difference
30 mph	30.0 mph	30.6 mph	+0.6 mph
60 mph	60.0 mph	61.1 mph	+1.1 mph
75 mph	75.0 mph	76.4 mph	+1.4 mph

Ride-height change: 265/70R15 raises the vehicle by 0.28 in (7.0 mm) at the axle (half the +14.0 mm diameter difference).

265/70R15 is 0.55 in taller than 255/70R15 and 10 mm wider, a 1.90% difference in overall diameter.

With the speedometer calibrated for 255/70R15, an indicated 60 mph is actually 61.1 mph on 265/70R15, and revolutions per mile change from 694 to 681.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 255/70R15

Other comparisons with 265/70R15

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