225/70R15 vs 235/70R15

235/70R15 is 0.55 in (14.0 mm) taller than 225/70R15, a +2.01% diameter difference. With the speedometer set for 225/70R15, an indicated 60 mph is 61.2 mph on 235/70R15.

Is this a safe swap?

Diameter difference +2.01%: within the ±3% guideline

By overall diameter alone, 235/70R15 falls inside the ±3% range commonly used as a guideline when replacing 225/70R15. 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.

225/70R15 vs 235/70R15 differences
Measurement	225/70R15	235/70R15	Difference	% diff
Overall diameter	27.40 in (696.0 mm)	27.95 in (710.0 mm)	+0.55 in (+14.0 mm)	+2.01%
Sidewall height	6.20 in (157.5 mm)	6.48 in (164.5 mm)	+0.28 in (+7.0 mm)	+4.44%
Section width	8.86 in (225.0 mm)	9.25 in (235.0 mm)	+0.39 in (+10.0 mm)	+4.44%
Circumference	86.08 in (2,186.5 mm)	87.82 in (2,230.5 mm)	+1.73 in (+44.0 mm)	+2.01%
Revolutions per mile	736	722	−15	−1.97%

True speed with the speedometer calibrated for 225/70R15
Indicated	Actual on 225/70R15	Actual on 235/70R15	Difference
30 mph	30.0 mph	30.6 mph	+0.6 mph
60 mph	60.0 mph	61.2 mph	+1.2 mph
75 mph	75.0 mph	76.5 mph	+1.5 mph

Ride-height change: 235/70R15 raises the vehicle by 0.28 in (7.0 mm) at the axle (half the +14.0 mm diameter difference).

235/70R15 is 0.55 in taller than 225/70R15 and 10 mm wider, a 2.01% difference in overall diameter.

With the speedometer calibrated for 225/70R15, an indicated 60 mph is actually 61.2 mph on 235/70R15, and revolutions per mile change from 736 to 722.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 225/70R15

Other comparisons with 235/70R15

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