TireSizesFinder

225/55R17 vs 245/55R17

245/55R17 is 0.87 in (22.0 mm) taller than 225/55R17, a +3.24% diameter difference. With the speedometer set for 225/55R17, an indicated 60 mph is 61.9 mph on 245/55R17.

Is this a safe swap?

Diameter difference +3.24%: outside the ±3% guideline

By overall diameter alone, 245/55R17 falls outside the ±3% range commonly used as a guideline when replacing 225/55R17; speedometer and ride-height changes are larger. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 225/55R17 (26.74 in) vs 245/55R17 (27.61 in)225/55R1726.74 in × 8.86 in245/55R1727.61 in × 9.65 in
Side profile and tread width, drawn to the same scale.
225/55R17 vs 245/55R17 differences
Measurement225/55R17245/55R17Difference% diff
Overall diameter26.74 in (679.3 mm)27.61 in (701.3 mm)+0.87 in (+22.0 mm)+3.24%
Sidewall height4.87 in (123.8 mm)5.31 in (134.8 mm)+0.43 in (+11.0 mm)+8.89%
Section width8.86 in (225.0 mm)9.65 in (245.0 mm)+0.79 in (+20.0 mm)+8.89%
Circumference84.02 in (2,134.1 mm)86.74 in (2,203.2 mm)+2.72 in (+69.1 mm)+3.24%
Revolutions per mile754730−24−3.14%
True speed with the speedometer calibrated for 225/55R17
IndicatedActual on 225/55R17Actual on 245/55R17Difference
30 mph30.0 mph31.0 mph+1.0 mph
60 mph60.0 mph61.9 mph+1.9 mph
75 mph75.0 mph77.4 mph+2.4 mph

Ride-height change: 245/55R17 raises the vehicle by 0.43 in (11.0 mm) at the axle (half the +22.0 mm diameter difference).

245/55R17 is 0.87 in taller than 225/55R17 and 20 mm wider, a 3.24% difference in overall diameter.

With the speedometer calibrated for 225/55R17, an indicated 60 mph is actually 61.9 mph on 245/55R17, and revolutions per mile change from 754 to 730.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 225/55R17

Other comparisons with 245/55R17

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.