235/85R16 vs 265/70R17

265/70R17 is 0.12 in (3.1 mm) shorter than 235/85R16, a −0.38% diameter difference. With the speedometer set for 235/85R16, an indicated 60 mph is 59.8 mph on 265/70R17.

Is this a safe swap?

Diameter difference −0.38%: under 1%

By overall diameter alone, 265/70R17 is a near match for 235/85R16; 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.

235/85R16 vs 265/70R17 differences
Measurement	235/85R16	265/70R17	Difference	% diff
Overall diameter	31.73 in (805.9 mm)	31.61 in (802.8 mm)	−0.12 in (−3.1 mm)	−0.38%
Sidewall height	7.86 in (199.8 mm)	7.30 in (185.5 mm)	−0.56 in (−14.2 mm)	−7.13%
Section width	9.25 in (235.0 mm)	10.43 in (265.0 mm)	+1.18 in (+30.0 mm)	+12.77%
Circumference	99.68 in (2,531.8 mm)	99.29 in (2,522.1 mm)	−0.38 in (−9.7 mm)	−0.38%
Revolutions per mile	636	638	+2	+0.39%

True speed with the speedometer calibrated for 235/85R16
Indicated	Actual on 235/85R16	Actual on 265/70R17	Difference
30 mph	30.0 mph	29.9 mph	−0.1 mph
60 mph	60.0 mph	59.8 mph	−0.2 mph
75 mph	75.0 mph	74.7 mph	−0.3 mph

Ride-height change: 265/70R17 lowers the vehicle by 0.06 in (1.6 mm) at the axle (half the −3.1 mm diameter difference).

265/70R17 is 0.12 in shorter than 235/85R16 and 30 mm wider, a 0.38% difference in overall diameter.

With the speedometer calibrated for 235/85R16, an indicated 60 mph is actually 59.8 mph on 265/70R17, and revolutions per mile change from 636 to 638.

265/70R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 235/85R16.

Size pages

Other comparisons with 235/85R16

Other comparisons with 265/70R17

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