295/60R20 vs 315/60R20

315/60R20 is 0.94 in (24.0 mm) taller than 295/60R20, a +2.78% diameter difference. With the speedometer set for 295/60R20, an indicated 60 mph is 61.7 mph on 315/60R20.

Is this a safe swap?

Diameter difference +2.78%: within the ±3% guideline

By overall diameter alone, 315/60R20 falls inside the ±3% range commonly used as a guideline when replacing 295/60R20. 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.

295/60R20 vs 315/60R20 differences
Measurement	295/60R20	315/60R20	Difference	% diff
Overall diameter	33.94 in (862.0 mm)	34.88 in (886.0 mm)	+0.94 in (+24.0 mm)	+2.78%
Sidewall height	6.97 in (177.0 mm)	7.44 in (189.0 mm)	+0.47 in (+12.0 mm)	+6.78%
Section width	11.61 in (295.0 mm)	12.40 in (315.0 mm)	+0.79 in (+20.0 mm)	+6.78%
Circumference	106.62 in (2,708.1 mm)	109.58 in (2,783.5 mm)	+2.97 in (+75.4 mm)	+2.78%
Revolutions per mile	594	578	−16	−2.71%

True speed with the speedometer calibrated for 295/60R20
Indicated	Actual on 295/60R20	Actual on 315/60R20	Difference
30 mph	30.0 mph	30.8 mph	+0.8 mph
60 mph	60.0 mph	61.7 mph	+1.7 mph
75 mph	75.0 mph	77.1 mph	+2.1 mph

Ride-height change: 315/60R20 raises the vehicle by 0.47 in (12.0 mm) at the axle (half the +24.0 mm diameter difference).

315/60R20 is 0.94 in taller than 295/60R20 and 20 mm wider, a 2.78% difference in overall diameter.

With the speedometer calibrated for 295/60R20, an indicated 60 mph is actually 61.7 mph on 315/60R20, and revolutions per mile change from 594 to 578.

Both sizes mount on 20-inch wheels.

Size pages

Other comparisons with 295/60R20

Other comparisons with 315/60R20

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