285/75R16 vs 255/85R16

255/85R16 is 0.24 in (6.0 mm) taller than 285/75R16, a +0.72% diameter difference. With the speedometer set for 285/75R16, an indicated 60 mph is 60.4 mph on 255/85R16.

Is this a safe swap?

Diameter difference +0.72%: under 1%

By overall diameter alone, 255/85R16 is a near match for 285/75R16; 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.

285/75R16 vs 255/85R16 differences
Measurement	285/75R16	255/85R16	Difference	% diff
Overall diameter	32.83 in (833.9 mm)	33.07 in (839.9 mm)	+0.24 in (+6.0 mm)	+0.72%
Sidewall height	8.42 in (213.8 mm)	8.53 in (216.8 mm)	+0.12 in (+3.0 mm)	+1.40%
Section width	11.22 in (285.0 mm)	10.04 in (255.0 mm)	−1.18 in (−30.0 mm)	−10.53%
Circumference	103.14 in (2,619.8 mm)	103.88 in (2,638.6 mm)	+0.74 in (+18.8 mm)	+0.72%
Revolutions per mile	614	610	−4	−0.71%

True speed with the speedometer calibrated for 285/75R16
Indicated	Actual on 285/75R16	Actual on 255/85R16	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.4 mph	+0.4 mph
75 mph	75.0 mph	75.5 mph	+0.5 mph

Ride-height change: 255/85R16 raises the vehicle by 0.12 in (3.0 mm) at the axle (half the +6.0 mm diameter difference).

255/85R16 is 0.24 in taller than 285/75R16 and 30 mm narrower, a 0.72% difference in overall diameter.

With the speedometer calibrated for 285/75R16, an indicated 60 mph is actually 60.4 mph on 255/85R16, and revolutions per mile change from 614 to 610.

Both sizes mount on 16-inch wheels.

Size pages

Other comparisons with 285/75R16

Other comparisons with 255/85R16

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