275/40R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
The 275/40R21 tire size features an overall diameter of 29.66 inches, a section width of 10.8 inches (275mm), and rotates 680 times per mile. It is a standard factory tire fitment on 35+ vehicle models including Acura MDX.
Physical Dimensions & Specs
Overall Diameter
29.66"
753.4 mmSection Width
275 mm
10.83" wideSidewall Height
4.33"
110.0 mm (40% aspect)Revolutions / Mile
680
Circumference: 93.18"Rim Diameter
21"
Wheel sizeRecommended Rim Width
6.9" - 9.6"
Optimal rim width rangeWhere to Buy & Install 275/40R21 Tires
Looking for 275/40R21 tires? Skip hauling tires in your car—choose direct delivery to a local certified shop or doorstep delivery:
Tire Rack
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Amazon Automotive
Fast doorstep shipping for DIYers or bringing to your own shop.
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Speedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 275/40R21 against any proposed tire size below:
Visual Tire & Wheel Comparison
Speedometer Variance
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 19.9 mph | -0.1 mph |
| 30 mph | 29.9 mph | -0.1 mph |
| 45 mph | 44.9 mph | -0.1 mph |
| 60 mph | 59.8 mph | -0.2 mph |
| 75 mph | 74.8 mph | -0.2 mph |
| 90 mph | 89.7 mph | -0.3 mph |
Fender & Suspension Clearance
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Vehicles That Fit 275/40R21 (35+ Models)
Factory standard and optional vehicle fitments utilizing 275/40R21 tires: