tire

Tire Size Calculator

Calculate tire sizes in inches or millimeters and find alternative sizes.
Tread Width: 305
  • 125
  • 130
  • 145
  • 155
  • 165
  • 175
  • 185
  • 195
  • 205
  • 215
  • 225
  • 235
  • 245
  • 255
  • 265
  • 275
  • 285
  • 295
  • 305
  • 315
  • 325
  • 335
  • 345
  • 355
  • 365
Aspect Ratio: 30
  • 20
  • 25
  • 30
  • 35
  • 40
  • 45
  • 50
  • 55
  • 60
  • 65
  • 70
  • 75
  • 80
  • 85
  • 90
  • 95
Wheel Diameter: 21
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
Inches
Millimeters

Results for 305/30R21 Tires

disc wheel
Diameter
28.2"
tire width
Width
12"
disc wheel
Sidewall
3.6"
tire circumference
Circumference
88.6"
tire rpm
Revs per mile
715
        

            

                
Alternate Tire Sizes

                

                

                                            

                            

                                21"
                            

                        
                    
                                                                        

                                    

                                        14"
                                    

                                

                                                            

                                    

                                        15"
                                    

                                

                                                            

                                    

                                        16"
                                    

                                

                                                            

                                    

                                        17"
                                    

                                

                                                            

                                    

                                        18"
                                    

                                

                                                            

                                    

                                        19"
                                    

                                

                                                            

                                    

                                        20"
                                    

                                

                                                            

                                    

                                        22"
                                    

                                

                                            

                

                    

                                                    

                                

                                    
Tire Size

                                    
Diameter

                                    
Width

                                    
Sidewall

                                    
Circumference

                                    
Revs per mile

                                    

                                

                                                                
325/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,4"
-2.92%
12,8"
3,2"
86,0"
737
275/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,5"
-2.55%
10,8"
3,2"
86,3"
734
285/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,7"
-1.81%
11,2"
3,4"
87,1"
728
345/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,8"
-1.44%
13,6"
3,4"
87,3"
726
245/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,8"
-1.44%
9,6"
3,4"
87,1"
727
355/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,0"
-0.71%
14,0"
3,5"
87,9"
721

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
255/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,0"
-0.71%
10,0"
3,5"
88,0"
720

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
295/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,0"
-0.71%
11,6"
3,5"
87,8"
722

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
305/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,2"
0%
12,0"
3,6"
88,6"
715

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
265/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,3"
0.35%
10,4"
3,7"
88,9"
713

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
315/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,4"
0.7%
12,4"
3,7"
89,3"
710

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
275/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,6"
1.4%
10,8"
3,8"
89,7"
706
245/40R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,7"
1.74%
9,6"
3,9"
90,2"
703
325/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,7"
1.74%
12,8"
3,8"
90,0"
704
335/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,9"
2.42%
13,2"
4,0"
90,8"
698
285/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,9"
2.42%
11,2"
3,9"
90,6"
699
255/40R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,0"
2.76%
10,0"
4,0"
91,2"
695