285/45R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
The 285/45R21 tire size features an overall diameter of 31.1 inches, a section width of 11.2 inches (285mm), and rotates 649 times per mile. It is a standard factory tire fitment on 53+ vehicle models including Audi Q8.
Physical Dimensions & Specs
Overall Diameter
31.1"
789.9 mmSection Width
285 mm
11.22" wideSidewall Height
5.05"
128.3 mm (45% aspect)Revolutions / Mile
649
Circumference: 97.7"Rim Diameter
21"
Wheel sizeRecommended Rim Width
7.1" - 10"
Optimal rim width rangeWhere to Buy & Install 285/45R21 Tires
Looking for 285/45R21 tires? Skip hauling tires in your car—choose direct delivery to a local certified shop or doorstep delivery:
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Speedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 285/45R21 against any proposed tire size below:
Visual Tire & Wheel Comparison
Speedometer Variance
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 19.0 mph | -1.0 mph |
| 30 mph | 28.5 mph | -1.5 mph |
| 45 mph | 42.8 mph | -2.2 mph |
| 60 mph | 57.1 mph | -2.9 mph |
| 75 mph | 71.3 mph | -3.7 mph |
| 90 mph | 85.6 mph | -4.4 mph |
Fender & Suspension Clearance
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Vehicles That Fit 285/45R21 (53+ Models)
Factory standard and optional vehicle fitments utilizing 285/45R21 tires: