255/70R15 vs 225/75R16

225/75R16 is 0.23 in (5.9 mm) taller than 255/70R15, a +0.80% diameter difference. With the speedometer set for 255/70R15, an indicated 60 mph is 60.5 mph on 225/75R16.

Is this a safe swap?

Diameter difference +0.80%: under 1%

By overall diameter alone, 225/75R16 is a near match for 255/70R15; 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.

255/70R15 vs 225/75R16 differences
Measurement	255/70R15	225/75R16	Difference	% diff
Overall diameter	29.06 in (738.0 mm)	29.29 in (743.9 mm)	+0.23 in (+5.9 mm)	+0.80%
Sidewall height	7.03 in (178.5 mm)	6.64 in (168.8 mm)	−0.38 in (−9.7 mm)	−5.46%
Section width	10.04 in (255.0 mm)	8.86 in (225.0 mm)	−1.18 in (−30.0 mm)	−11.76%
Circumference	91.28 in (2,318.5 mm)	92.01 in (2,337.0 mm)	+0.73 in (+18.5 mm)	+0.80%
Revolutions per mile	694	689	−6	−0.79%

True speed with the speedometer calibrated for 255/70R15
Indicated	Actual on 255/70R15	Actual on 225/75R16	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.5 mph	+0.5 mph
75 mph	75.0 mph	75.6 mph	+0.6 mph

Ride-height change: 225/75R16 raises the vehicle by 0.12 in (2.9 mm) at the axle (half the +5.9 mm diameter difference).

225/75R16 is 0.23 in taller than 255/70R15 and 30 mm narrower, a 0.80% difference in overall diameter.

With the speedometer calibrated for 255/70R15, an indicated 60 mph is actually 60.5 mph on 225/75R16, and revolutions per mile change from 694 to 689.

225/75R16 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 225/75R16

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