235/50R17 vs 215/55R17

215/55R17 is 0.06 in (1.5 mm) taller than 235/50R17, a +0.22% diameter difference. With the speedometer set for 235/50R17, an indicated 60 mph is 60.1 mph on 215/55R17.

Is this a safe swap?

Diameter difference +0.22%: under 1%

By overall diameter alone, 215/55R17 is a near match for 235/50R17; 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.

235/50R17 vs 215/55R17 differences
Measurement	235/50R17	215/55R17	Difference	% diff
Overall diameter	26.25 in (666.8 mm)	26.31 in (668.3 mm)	+0.06 in (+1.5 mm)	+0.22%
Sidewall height	4.63 in (117.5 mm)	4.66 in (118.3 mm)	+0.03 in (+0.8 mm)	+0.64%
Section width	9.25 in (235.0 mm)	8.46 in (215.0 mm)	−0.79 in (−20.0 mm)	−8.51%
Circumference	82.47 in (2,094.8 mm)	82.66 in (2,099.5 mm)	+0.19 in (+4.7 mm)	+0.22%
Revolutions per mile	768	767	−2	−0.22%

True speed with the speedometer calibrated for 235/50R17
Indicated	Actual on 235/50R17	Actual on 215/55R17	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.1 mph	+0.1 mph
75 mph	75.0 mph	75.2 mph	+0.2 mph

Ride-height change: 215/55R17 raises the vehicle by 0.03 in (0.8 mm) at the axle (half the +1.5 mm diameter difference).

215/55R17 is 0.06 in taller than 235/50R17 and 20 mm narrower, a 0.22% difference in overall diameter.

With the speedometer calibrated for 235/50R17, an indicated 60 mph is actually 60.1 mph on 215/55R17, and revolutions per mile change from 768 to 767.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 235/50R17

Other comparisons with 215/55R17

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