245/50R17 vs 225/55R17

225/55R17 is 0.10 in (2.5 mm) taller than 245/50R17, a +0.37% diameter difference. With the speedometer set for 245/50R17, an indicated 60 mph is 60.2 mph on 225/55R17.

Is this a safe swap?

Diameter difference +0.37%: under 1%

By overall diameter alone, 225/55R17 is a near match for 245/50R17; 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.

245/50R17 vs 225/55R17 differences
Measurement	245/50R17	225/55R17	Difference	% diff
Overall diameter	26.65 in (676.8 mm)	26.74 in (679.3 mm)	+0.10 in (+2.5 mm)	+0.37%
Sidewall height	4.82 in (122.5 mm)	4.87 in (123.8 mm)	+0.05 in (+1.3 mm)	+1.02%
Section width	9.65 in (245.0 mm)	8.86 in (225.0 mm)	−0.79 in (−20.0 mm)	−8.16%
Circumference	83.71 in (2,126.2 mm)	84.02 in (2,134.1 mm)	+0.31 in (+7.9 mm)	+0.37%
Revolutions per mile	757	754	−3	−0.37%

True speed with the speedometer calibrated for 245/50R17
Indicated	Actual on 245/50R17	Actual on 225/55R17	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.2 mph	+0.2 mph
75 mph	75.0 mph	75.3 mph	+0.3 mph

Ride-height change: 225/55R17 raises the vehicle by 0.05 in (1.3 mm) at the axle (half the +2.5 mm diameter difference).

225/55R17 is 0.10 in taller than 245/50R17 and 20 mm narrower, a 0.37% difference in overall diameter.

With the speedometer calibrated for 245/50R17, an indicated 60 mph is actually 60.2 mph on 225/55R17, and revolutions per mile change from 757 to 754.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 245/50R17

Other comparisons with 225/55R17

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