TireSizesFinder

295/40R20 vs 265/40R21

265/40R21 is 0.06 in (1.4 mm) taller than 295/40R20, a +0.19% diameter difference. With the speedometer set for 295/40R20, an indicated 60 mph is 60.1 mph on 265/40R21.

Is this a safe swap?

Diameter difference +0.19%: under 1%

By overall diameter alone, 265/40R21 is a near match for 295/40R20; 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: 295/40R20 (29.29 in) vs 265/40R21 (29.35 in)295/40R2029.29 in × 11.61 in265/40R2129.35 in × 10.43 in
Side profile and tread width, drawn to the same scale.
295/40R20 vs 265/40R21 differences
Measurement295/40R20265/40R21Difference% diff
Overall diameter29.29 in (744.0 mm)29.35 in (745.4 mm)+0.06 in (+1.4 mm)+0.19%
Sidewall height4.65 in (118.0 mm)4.17 in (106.0 mm)−0.47 in (−12.0 mm)−10.17%
Section width11.61 in (295.0 mm)10.43 in (265.0 mm)−1.18 in (−30.0 mm)−10.17%
Circumference92.02 in (2,337.3 mm)92.19 in (2,341.7 mm)+0.17 in (+4.4 mm)+0.19%
Revolutions per mile689687−1−0.19%
True speed with the speedometer calibrated for 295/40R20
IndicatedActual on 295/40R20Actual on 265/40R21Difference
30 mph30.0 mph30.1 mph+0.1 mph
60 mph60.0 mph60.1 mph+0.1 mph
75 mph75.0 mph75.1 mph+0.1 mph

Ride-height change: 265/40R21 raises the vehicle by 0.03 in (0.7 mm) at the axle (half the +1.4 mm diameter difference).

265/40R21 is 0.06 in taller than 295/40R20 and 30 mm narrower, a 0.19% difference in overall diameter.

With the speedometer calibrated for 295/40R20, an indicated 60 mph is actually 60.1 mph on 265/40R21, and revolutions per mile change from 689 to 687.

265/40R21 mounts on a 21-inch wheel, a plus-1 fitment from the 20-inch wheel of 295/40R20.

Size pages

Other comparisons with 295/40R20

Other comparisons with 265/40R21

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