tire

Tire Size Calculator

Calculate tire sizes in inches or millimeters and find alternative sizes.
Tread Width: 255
  • 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 255/30R21 Tires

disc wheel
Diameter
27"
tire width
Width
10"
disc wheel
Sidewall
3"
tire circumference
Circumference
84.9"
tire rpm
Revs per mile
747
        

            

                
Alternate Tire Sizes

                

                

                                            

                            

                                21"
                            

                        
                    
                                                                        

                                    

                                        14"
                                    

                                

                                                            

                                    

                                        15"
                                    

                                

                                                            

                                    

                                        16"
                                    

                                

                                                            

                                    

                                        17"
                                    

                                

                                                            

                                    

                                        18"
                                    

                                

                                                            

                                    

                                        19"
                                    

                                

                                                            

                                    

                                        20"
                                    

                                

                                                            

                                    

                                        22"
                                    

                                

                                            

                

                    

                                                    

                                

                                    
Tire Size

                                    
Diameter

                                    
Width

                                    
Sidewall

                                    
Circumference

                                    
Revs per mile

                                    

                                

                                                                
275/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
26,4"
-2.27%
10,8"
2,7"
82,9"
764
235/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
26,6"
-1.5%
9,3"
2,8"
83,4"
760
245/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
26,8"
-0.75%
9,6"
2,9"
84,1"
753

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
295/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
26,8"
-0.75%
11,6"
2,9"
84,2"
753

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
305/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,0"
0%
12,0"
3,0"
84,8"
747

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
255/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,0"
0%
10,0"
3,0"
84,9"
747

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
265/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,3"
1.1%
10,4"
3,1"
85,6"
740
325/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,4"
1.46%
12,8"
3,2"
86,0"
737
275/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,5"
1.82%
10,8"
3,2"
86,3"
734
285/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,7"
2.53%
11,2"
3,4"
87,1"
728
345/25R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,8"
2.88%
13,6"
3,4"
87,3"
726
245/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
27,8"
2.88%
9,6"
3,4"
87,1"
727