285/35R19 vs 295/30R20

295/30R20 is 0.11 in (2.9 mm) taller than 285/35R19, a +0.43% diameter difference. With the speedometer set for 285/35R19, an indicated 60 mph is 60.3 mph on 295/30R20.

Is this a safe swap?

Diameter difference +0.43%: under 1%

By overall diameter alone, 295/30R20 is a near match for 285/35R19; 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.

285/35R19 vs 295/30R20 differences
Measurement	285/35R19	295/30R20	Difference	% diff
Overall diameter	26.85 in (682.1 mm)	26.97 in (685.0 mm)	+0.11 in (+2.9 mm)	+0.43%
Sidewall height	3.93 in (99.8 mm)	3.48 in (88.5 mm)	−0.44 in (−11.2 mm)	−11.28%
Section width	11.22 in (285.0 mm)	11.61 in (295.0 mm)	+0.39 in (+10.0 mm)	+3.51%
Circumference	84.37 in (2,142.9 mm)	84.72 in (2,152.0 mm)	+0.36 in (+9.1 mm)	+0.43%
Revolutions per mile	751	748	−3	−0.42%

True speed with the speedometer calibrated for 285/35R19
Indicated	Actual on 285/35R19	Actual on 295/30R20	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.3 mph	+0.3 mph

Ride-height change: 295/30R20 raises the vehicle by 0.06 in (1.5 mm) at the axle (half the +2.9 mm diameter difference).

295/30R20 is 0.11 in taller than 285/35R19 and 10 mm wider, a 0.43% difference in overall diameter.

With the speedometer calibrated for 285/35R19, an indicated 60 mph is actually 60.3 mph on 295/30R20, and revolutions per mile change from 751 to 748.

295/30R20 mounts on a 20-inch wheel, a plus-1 fitment from the 19-inch wheel of 285/35R19.

Size pages

Other comparisons with 285/35R19

Other comparisons with 295/30R20

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