TireSizesFinder

285/65R18 vs 295/55R20

295/55R20 is 0.19 in (4.8 mm) taller than 285/65R18, a +0.58% diameter difference. With the speedometer set for 285/65R18, an indicated 60 mph is 60.3 mph on 295/55R20.

Is this a safe swap?

Diameter difference +0.58%: under 1%

By overall diameter alone, 295/55R20 is a near match for 285/65R18; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 285/65R18 (32.59 in) vs 295/55R20 (32.78 in)285/65R1832.59 in × 11.22 in295/55R2032.78 in × 11.61 in
Side profile and tread width, drawn to the same scale.
285/65R18 vs 295/55R20 differences
Measurement285/65R18295/55R20Difference% diff
Overall diameter32.59 in (827.7 mm)32.78 in (832.5 mm)+0.19 in (+4.8 mm)+0.58%
Sidewall height7.29 in (185.3 mm)6.39 in (162.3 mm)−0.91 in (−23.0 mm)−12.42%
Section width11.22 in (285.0 mm)11.61 in (295.0 mm)+0.39 in (+10.0 mm)+3.51%
Circumference102.37 in (2,600.3 mm)102.97 in (2,615.4 mm)+0.59 in (+15.1 mm)+0.58%
Revolutions per mile619615−4−0.58%
True speed with the speedometer calibrated for 285/65R18
IndicatedActual on 285/65R18Actual on 295/55R20Difference
30 mph30.0 mph30.2 mph+0.2 mph
60 mph60.0 mph60.3 mph+0.3 mph
75 mph75.0 mph75.4 mph+0.4 mph

Ride-height change: 295/55R20 raises the vehicle by 0.09 in (2.4 mm) at the axle (half the +4.8 mm diameter difference).

295/55R20 is 0.19 in taller than 285/65R18 and 10 mm wider, a 0.58% difference in overall diameter.

With the speedometer calibrated for 285/65R18, an indicated 60 mph is actually 60.3 mph on 295/55R20, and revolutions per mile change from 619 to 615.

295/55R20 mounts on a 20-inch wheel, a plus-2 fitment from the 18-inch wheel of 285/65R18.

Size pages

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