255/70R15 vs 245/65R16

245/65R16 is 0.52 in (13.1 mm) shorter than 255/70R15, a −1.78% diameter difference. With the speedometer set for 255/70R15, an indicated 60 mph is 58.9 mph on 245/65R16.

Is this a safe swap?

Diameter difference −1.78%: within the ±3% guideline

By overall diameter alone, 245/65R16 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 245/65R16 differences
Measurement	255/70R15	245/65R16	Difference	% diff
Overall diameter	29.06 in (738.0 mm)	28.54 in (724.9 mm)	−0.52 in (−13.1 mm)	−1.78%
Sidewall height	7.03 in (178.5 mm)	6.27 in (159.3 mm)	−0.76 in (−19.2 mm)	−10.78%
Section width	10.04 in (255.0 mm)	9.65 in (245.0 mm)	−0.39 in (−10.0 mm)	−3.92%
Circumference	91.28 in (2,318.5 mm)	89.66 in (2,277.3 mm)	−1.62 in (−41.2 mm)	−1.78%
Revolutions per mile	694	707	+13	+1.81%

True speed with the speedometer calibrated for 255/70R15
Indicated	Actual on 255/70R15	Actual on 245/65R16	Difference
30 mph	30.0 mph	29.5 mph	−0.5 mph
60 mph	60.0 mph	58.9 mph	−1.1 mph
75 mph	75.0 mph	73.7 mph	−1.3 mph

Ride-height change: 245/65R16 lowers the vehicle by 0.26 in (6.6 mm) at the axle (half the −13.1 mm diameter difference).

245/65R16 is 0.52 in shorter than 255/70R15 and 10 mm narrower, a 1.78% difference in overall diameter.

With the speedometer calibrated for 255/70R15, an indicated 60 mph is actually 58.9 mph on 245/65R16, and revolutions per mile change from 694 to 707.

245/65R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 255/70R15.

Size pages

Other comparisons with 255/70R15

Other comparisons with 245/65R16

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