TireSizesFinder

295/35R21 vs 265/40R21

265/40R21 is 0.22 in (5.5 mm) taller than 295/35R21, a +0.74% diameter difference. With the speedometer set for 295/35R21, an indicated 60 mph is 60.4 mph on 265/40R21.

Is this a safe swap?

Diameter difference +0.74%: under 1%

By overall diameter alone, 265/40R21 is a near match for 295/35R21; 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: 295/35R21 (29.13 in) vs 265/40R21 (29.35 in)295/35R2129.13 in × 11.61 in265/40R2129.35 in × 10.43 in
Side profile and tread width, drawn to the same scale.
295/35R21 vs 265/40R21 differences
Measurement295/35R21265/40R21Difference% diff
Overall diameter29.13 in (739.9 mm)29.35 in (745.4 mm)+0.22 in (+5.5 mm)+0.74%
Sidewall height4.06 in (103.3 mm)4.17 in (106.0 mm)+0.11 in (+2.8 mm)+2.66%
Section width11.61 in (295.0 mm)10.43 in (265.0 mm)−1.18 in (−30.0 mm)−10.17%
Circumference91.51 in (2,324.5 mm)92.19 in (2,341.7 mm)+0.68 in (+17.3 mm)+0.74%
Revolutions per mile692687−5−0.74%
True speed with the speedometer calibrated for 295/35R21
IndicatedActual on 295/35R21Actual on 265/40R21Difference
30 mph30.0 mph30.2 mph+0.2 mph
60 mph60.0 mph60.4 mph+0.4 mph
75 mph75.0 mph75.6 mph+0.6 mph

Ride-height change: 265/40R21 raises the vehicle by 0.11 in (2.8 mm) at the axle (half the +5.5 mm diameter difference).

265/40R21 is 0.22 in taller than 295/35R21 and 30 mm narrower, a 0.74% difference in overall diameter.

With the speedometer calibrated for 295/35R21, an indicated 60 mph is actually 60.4 mph on 265/40R21, and revolutions per mile change from 692 to 687.

Both sizes mount on 21-inch wheels.

Size pages

Other comparisons with 295/35R21

Other comparisons with 265/40R21

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