255/50R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The 255/50R21 tire size features an overall diameter of 31.04 inches, a section width of 10.0 inches (255mm), and rotates 650 times per mile. It is a standard factory tire fitment on 9+ vehicle models including BMW iX.
Physical Dimensions & Specs
Overall Diameter
31.04"
788.4 mmSection Width
255 mm
10.04" wideSidewall Height
5.02"
127.5 mm (50% aspect)Revolutions / Mile
650
Circumference: 97.51"Rim Diameter
21"
Wheel sizeRecommended Rim Width
6.4" - 8.9"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 255/50R21 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)255/50R21
Overall Height:31.0"
Sidewall:5.0"
Revs/Mile:650
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
-4.7%At 60 mph reading, actual speed is 57.2 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 19.1 mph | -0.9 mph |
| 30 mph | 28.6 mph | -1.4 mph |
| 45 mph | 42.9 mph | -2.1 mph |
| 60 mph | 57.2 mph | -2.8 mph |
| 75 mph | 71.5 mph | -3.5 mph |
| 90 mph | 85.8 mph | -4.2 mph |
Fender & Suspension Clearance
Fitment Status: MODERATE RISK
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Inner Strut Space:7.7mm LESS clearance
Outer Fender Push:Extends 17.7mm further out
Ride Height Delta:-0.73" lower ground clearance
Vehicles That Fit 255/50R21 (9+ Models)
Factory standard and optional vehicle fitments utilizing 255/50R21 tires: