215/75R15 vs 235/70R15

235/70R15 is 0.26 in (6.5 mm) taller than 215/75R15, a +0.92% diameter difference. With the speedometer set for 215/75R15, an indicated 60 mph is 60.6 mph on 235/70R15.

Is this a safe swap?

Diameter difference +0.92%: under 1%

By overall diameter alone, 235/70R15 is a near match for 215/75R15; 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.

215/75R15 vs 235/70R15 differences
Measurement	215/75R15	235/70R15	Difference	% diff
Overall diameter	27.70 in (703.5 mm)	27.95 in (710.0 mm)	+0.26 in (+6.5 mm)	+0.92%
Sidewall height	6.35 in (161.3 mm)	6.48 in (164.5 mm)	+0.13 in (+3.3 mm)	+2.02%
Section width	8.46 in (215.0 mm)	9.25 in (235.0 mm)	+0.79 in (+20.0 mm)	+9.30%
Circumference	87.01 in (2,210.1 mm)	87.82 in (2,230.5 mm)	+0.80 in (+20.4 mm)	+0.92%
Revolutions per mile	728	722	−7	−0.92%

True speed with the speedometer calibrated for 215/75R15
Indicated	Actual on 215/75R15	Actual on 235/70R15	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.6 mph	+0.6 mph
75 mph	75.0 mph	75.7 mph	+0.7 mph

Ride-height change: 235/70R15 raises the vehicle by 0.13 in (3.3 mm) at the axle (half the +6.5 mm diameter difference).

235/70R15 is 0.26 in taller than 215/75R15 and 20 mm wider, a 0.92% difference in overall diameter.

With the speedometer calibrated for 215/75R15, an indicated 60 mph is actually 60.6 mph on 235/70R15, and revolutions per mile change from 728 to 722.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 215/75R15

Other comparisons with 235/70R15

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