235/75R15 vs 225/70R16

225/70R16 is 0.48 in (12.1 mm) shorter than 235/75R15, a −1.65% diameter difference. With the speedometer set for 235/75R15, an indicated 60 mph is 59.0 mph on 225/70R16.

Is this a safe swap?

Diameter difference −1.65%: within the ±3% guideline

By overall diameter alone, 225/70R16 falls inside the ±3% range commonly used as a guideline when replacing 235/75R15. 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.

235/75R15 vs 225/70R16 differences
Measurement	235/75R15	225/70R16	Difference	% diff
Overall diameter	28.88 in (733.5 mm)	28.40 in (721.4 mm)	−0.48 in (−12.1 mm)	−1.65%
Sidewall height	6.94 in (176.3 mm)	6.20 in (157.5 mm)	−0.74 in (−18.7 mm)	−10.64%
Section width	9.25 in (235.0 mm)	8.86 in (225.0 mm)	−0.39 in (−10.0 mm)	−4.26%
Circumference	90.72 in (2,304.4 mm)	89.23 in (2,266.3 mm)	−1.50 in (−38.0 mm)	−1.65%
Revolutions per mile	698	710	+12	+1.68%

True speed with the speedometer calibrated for 235/75R15
Indicated	Actual on 235/75R15	Actual on 225/70R16	Difference
30 mph	30.0 mph	29.5 mph	−0.5 mph
60 mph	60.0 mph	59.0 mph	−1.0 mph
75 mph	75.0 mph	73.8 mph	−1.2 mph

Ride-height change: 225/70R16 lowers the vehicle by 0.24 in (6.1 mm) at the axle (half the −12.1 mm diameter difference).

225/70R16 is 0.48 in shorter than 235/75R15 and 10 mm narrower, a 1.65% difference in overall diameter.

With the speedometer calibrated for 235/75R15, an indicated 60 mph is actually 59.0 mph on 225/70R16, and revolutions per mile change from 698 to 710.

225/70R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 235/75R15.

Size pages

Other comparisons with 235/75R15

Other comparisons with 225/70R16

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