255/70R16 vs 215/85R16

215/85R16 is 0.33 in (8.5 mm) taller than 255/70R16, a +1.11% diameter difference. With the speedometer set for 255/70R16, an indicated 60 mph is 60.7 mph on 215/85R16.

Is this a safe swap?

Diameter difference +1.11%: within the ±3% guideline

By overall diameter alone, 215/85R16 falls inside the ±3% range commonly used as a guideline when replacing 255/70R16. 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.

255/70R16 vs 215/85R16 differences
Measurement	255/70R16	215/85R16	Difference	% diff
Overall diameter	30.06 in (763.4 mm)	30.39 in (771.9 mm)	+0.33 in (+8.5 mm)	+1.11%
Sidewall height	7.03 in (178.5 mm)	7.19 in (182.8 mm)	+0.17 in (+4.3 mm)	+2.38%
Section width	10.04 in (255.0 mm)	8.46 in (215.0 mm)	−1.57 in (−40.0 mm)	−15.69%
Circumference	94.42 in (2,398.3 mm)	95.47 in (2,425.0 mm)	+1.05 in (+26.7 mm)	+1.11%
Revolutions per mile	671	664	−7	−1.10%

True speed with the speedometer calibrated for 255/70R16
Indicated	Actual on 255/70R16	Actual on 215/85R16	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.7 mph	+0.7 mph
75 mph	75.0 mph	75.8 mph	+0.8 mph

Ride-height change: 215/85R16 raises the vehicle by 0.17 in (4.3 mm) at the axle (half the +8.5 mm diameter difference).

215/85R16 is 0.33 in taller than 255/70R16 and 40 mm narrower, a 1.11% difference in overall diameter.

With the speedometer calibrated for 255/70R16, an indicated 60 mph is actually 60.7 mph on 215/85R16, and revolutions per mile change from 671 to 664.

Both sizes mount on 16-inch wheels.

Size pages

Other comparisons with 255/70R16

Other comparisons with 215/85R16

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