TireSizesFinder

285/45R21 vs 265/50R21

265/50R21 is 0.33 in (8.5 mm) taller than 285/45R21, a +1.08% diameter difference. With the speedometer set for 285/45R21, an indicated 60 mph is 60.6 mph on 265/50R21.

Is this a safe swap?

Diameter difference +1.08%: within the ±3% guideline

By overall diameter alone, 265/50R21 falls inside the ±3% range commonly used as a guideline when replacing 285/45R21. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 285/45R21 (31.10 in) vs 265/50R21 (31.43 in)285/45R2131.10 in × 11.22 in265/50R2131.43 in × 10.43 in
Side profile and tread width, drawn to the same scale.
285/45R21 vs 265/50R21 differences
Measurement285/45R21265/50R21Difference% diff
Overall diameter31.10 in (789.9 mm)31.43 in (798.4 mm)+0.33 in (+8.5 mm)+1.08%
Sidewall height5.05 in (128.3 mm)5.22 in (132.5 mm)+0.17 in (+4.3 mm)+3.31%
Section width11.22 in (285.0 mm)10.43 in (265.0 mm)−0.79 in (−20.0 mm)−7.02%
Circumference97.70 in (2,481.5 mm)98.75 in (2,508.2 mm)+1.05 in (+26.7 mm)+1.08%
Revolutions per mile649642−7−1.06%
True speed with the speedometer calibrated for 285/45R21
IndicatedActual on 285/45R21Actual on 265/50R21Difference
30 mph30.0 mph30.3 mph+0.3 mph
60 mph60.0 mph60.6 mph+0.6 mph
75 mph75.0 mph75.8 mph+0.8 mph

Ride-height change: 265/50R21 raises the vehicle by 0.17 in (4.3 mm) at the axle (half the +8.5 mm diameter difference).

265/50R21 is 0.33 in taller than 285/45R21 and 20 mm narrower, a 1.08% difference in overall diameter.

With the speedometer calibrated for 285/45R21, an indicated 60 mph is actually 60.6 mph on 265/50R21, and revolutions per mile change from 649 to 642.

Both sizes mount on 21-inch wheels.

Size pages

Other comparisons with 285/45R21

Other comparisons with 265/50R21

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