235/70R15 vs 225/65R16

225/65R16 is 0.44 in (11.1 mm) shorter than 235/70R15, a −1.56% diameter difference. With the speedometer set for 235/70R15, an indicated 60 mph is 59.1 mph on 225/65R16.

Is this a safe swap?

Diameter difference −1.56%: within the ±3% guideline

By overall diameter alone, 225/65R16 falls inside the ±3% range commonly used as a guideline when replacing 235/70R15. 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.

235/70R15 vs 225/65R16 differences
Measurement	235/70R15	225/65R16	Difference	% diff
Overall diameter	27.95 in (710.0 mm)	27.52 in (698.9 mm)	−0.44 in (−11.1 mm)	−1.56%
Sidewall height	6.48 in (164.5 mm)	5.76 in (146.3 mm)	−0.72 in (−18.2 mm)	−11.09%
Section width	9.25 in (235.0 mm)	8.86 in (225.0 mm)	−0.39 in (−10.0 mm)	−4.26%
Circumference	87.82 in (2,230.5 mm)	86.44 in (2,195.7 mm)	−1.37 in (−34.9 mm)	−1.56%
Revolutions per mile	722	733	+11	+1.59%

True speed with the speedometer calibrated for 235/70R15
Indicated	Actual on 235/70R15	Actual on 225/65R16	Difference
30 mph	30.0 mph	29.5 mph	−0.5 mph
60 mph	60.0 mph	59.1 mph	−0.9 mph
75 mph	75.0 mph	73.8 mph	−1.2 mph

Ride-height change: 225/65R16 lowers the vehicle by 0.22 in (5.6 mm) at the axle (half the −11.1 mm diameter difference).

225/65R16 is 0.44 in shorter than 235/70R15 and 10 mm narrower, a 1.56% difference in overall diameter.

With the speedometer calibrated for 235/70R15, an indicated 60 mph is actually 59.1 mph on 225/65R16, and revolutions per mile change from 722 to 733.

225/65R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 235/70R15.

Size pages

Other comparisons with 235/70R15

Other comparisons with 225/65R16

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