TireSizesFinder

285/40R19 vs 295/30R21

295/30R21 is 0.01 in (0.2 mm) shorter than 285/40R19, a −0.03% diameter difference. With the speedometer set for 285/40R19, an indicated 60 mph is 60.0 mph on 295/30R21.

Is this a safe swap?

Diameter difference −0.03%: under 1%

By overall diameter alone, 295/30R21 is a near match for 285/40R19; 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: 285/40R19 (27.98 in) vs 295/30R21 (27.97 in)285/40R1927.98 in × 11.22 in295/30R2127.97 in × 11.61 in
Side profile and tread width, drawn to the same scale.
285/40R19 vs 295/30R21 differences
Measurement285/40R19295/30R21Difference% diff
Overall diameter27.98 in (710.6 mm)27.97 in (710.4 mm)−0.01 in (−0.2 mm)−0.03%
Sidewall height4.49 in (114.0 mm)3.48 in (88.5 mm)−1.00 in (−25.5 mm)−22.37%
Section width11.22 in (285.0 mm)11.61 in (295.0 mm)+0.39 in (+10.0 mm)+3.51%
Circumference87.89 in (2,232.4 mm)87.87 in (2,231.8 mm)−0.02 in (−0.6 mm)−0.03%
Revolutions per mile7217210+0.03%
True speed with the speedometer calibrated for 285/40R19
IndicatedActual on 285/40R19Actual on 295/30R21Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.0 mph0.0 mph
75 mph75.0 mph75.0 mph0.0 mph

Ride-height change: 295/30R21 lowers the vehicle by 0.00 in (0.1 mm) at the axle (half the −0.2 mm diameter difference).

295/30R21 is 0.01 in shorter than 285/40R19 and 10 mm wider, a 0.03% difference in overall diameter.

With the speedometer calibrated for 285/40R19, an indicated 60 mph is actually 60.0 mph on 295/30R21, and revolutions per mile change from 721 to 721.

295/30R21 mounts on a 21-inch wheel, a plus-2 fitment from the 19-inch wheel of 285/40R19.

Size pages

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