305/65R17 vs 295/70R17

295/70R17 is 0.65 in (16.5 mm) taller than 305/65R17, a +1.99% diameter difference. With the speedometer set for 305/65R17, an indicated 60 mph is 61.2 mph on 295/70R17.

Is this a safe swap?

Diameter difference +1.99%: within the ±3% guideline

By overall diameter alone, 295/70R17 falls inside the ±3% range commonly used as a guideline when replacing 305/65R17. 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.

305/65R17 vs 295/70R17 differences
Measurement	305/65R17	295/70R17	Difference	% diff
Overall diameter	32.61 in (828.3 mm)	33.26 in (844.8 mm)	+0.65 in (+16.5 mm)	+1.99%
Sidewall height	7.81 in (198.3 mm)	8.13 in (206.5 mm)	+0.32 in (+8.3 mm)	+4.16%
Section width	12.01 in (305.0 mm)	11.61 in (295.0 mm)	−0.39 in (−10.0 mm)	−3.28%
Circumference	102.45 in (2,602.2 mm)	104.49 in (2,654.0 mm)	+2.04 in (+51.8 mm)	+1.99%
Revolutions per mile	618	606	−12	−1.95%

True speed with the speedometer calibrated for 305/65R17
Indicated	Actual on 305/65R17	Actual on 295/70R17	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: 295/70R17 raises the vehicle by 0.32 in (8.3 mm) at the axle (half the +16.5 mm diameter difference).

295/70R17 is 0.65 in taller than 305/65R17 and 10 mm narrower, a 1.99% difference in overall diameter.

With the speedometer calibrated for 305/65R17, an indicated 60 mph is actually 61.2 mph on 295/70R17, and revolutions per mile change from 618 to 606.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 305/65R17

Other comparisons with 295/70R17

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