245/75R15 vs 265/70R15

265/70R15 is 0.14 in (3.5 mm) taller than 245/75R15, a +0.47% diameter difference. With the speedometer set for 245/75R15, an indicated 60 mph is 60.3 mph on 265/70R15.

Is this a safe swap?

Diameter difference +0.47%: under 1%

By overall diameter alone, 265/70R15 is a near match for 245/75R15; 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.

245/75R15 vs 265/70R15 differences
Measurement	245/75R15	265/70R15	Difference	% diff
Overall diameter	29.47 in (748.5 mm)	29.61 in (752.0 mm)	+0.14 in (+3.5 mm)	+0.47%
Sidewall height	7.23 in (183.8 mm)	7.30 in (185.5 mm)	+0.07 in (+1.8 mm)	+0.95%
Section width	9.65 in (245.0 mm)	10.43 in (265.0 mm)	+0.79 in (+20.0 mm)	+8.16%
Circumference	92.58 in (2,351.5 mm)	93.01 in (2,362.5 mm)	+0.43 in (+11.0 mm)	+0.47%
Revolutions per mile	684	681	−3	−0.47%

True speed with the speedometer calibrated for 245/75R15
Indicated	Actual on 245/75R15	Actual on 265/70R15	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 265/70R15 raises the vehicle by 0.07 in (1.8 mm) at the axle (half the +3.5 mm diameter difference).

265/70R15 is 0.14 in taller than 245/75R15 and 20 mm wider, a 0.47% difference in overall diameter.

With the speedometer calibrated for 245/75R15, an indicated 60 mph is actually 60.3 mph on 265/70R15, and revolutions per mile change from 684 to 681.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 245/75R15

Other comparisons with 265/70R15

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