235/65R17 vs 245/65R17

245/65R17 is 0.51 in (13.0 mm) taller than 235/65R17, a +1.76% diameter difference. With the speedometer set for 235/65R17, an indicated 60 mph is 61.1 mph on 245/65R17.

Is this a safe swap?

Diameter difference +1.76%: within the ±3% guideline

By overall diameter alone, 245/65R17 falls inside the ±3% range commonly used as a guideline when replacing 235/65R17. 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.

235/65R17 vs 245/65R17 differences
Measurement	235/65R17	245/65R17	Difference	% diff
Overall diameter	29.03 in (737.3 mm)	29.54 in (750.3 mm)	+0.51 in (+13.0 mm)	+1.76%
Sidewall height	6.01 in (152.8 mm)	6.27 in (159.3 mm)	+0.26 in (+6.5 mm)	+4.26%
Section width	9.25 in (235.0 mm)	9.65 in (245.0 mm)	+0.39 in (+10.0 mm)	+4.26%
Circumference	91.19 in (2,316.3 mm)	92.80 in (2,357.1 mm)	+1.61 in (+40.8 mm)	+1.76%
Revolutions per mile	695	683	−12	−1.73%

True speed with the speedometer calibrated for 235/65R17
Indicated	Actual on 235/65R17	Actual on 245/65R17	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	61.1 mph	+1.1 mph
75 mph	75.0 mph	76.3 mph	+1.3 mph

Ride-height change: 245/65R17 raises the vehicle by 0.26 in (6.5 mm) at the axle (half the +13.0 mm diameter difference).

245/65R17 is 0.51 in taller than 235/65R17 and 10 mm wider, a 1.76% difference in overall diameter.

With the speedometer calibrated for 235/65R17, an indicated 60 mph is actually 61.1 mph on 245/65R17, and revolutions per mile change from 695 to 683.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 235/65R17

Other comparisons with 245/65R17

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