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: 40
  • 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 255/40R21 Tires

disc wheel
Diameter
29"
tire width
Width
10"
disc wheel
Sidewall
4"
tire circumference
Circumference
91.2"
tire rpm
Revs per mile
695
        

            

                
Alternate Tire Sizes

                

                

                                            

                            

                                21"
                            

                        
                    
                                                                        

                                    

                                        15"
                                    

                                

                                                            

                                    

                                        16"
                                    

                                

                                                            

                                    

                                        17"
                                    

                                

                                                            

                                    

                                        18"
                                    

                                

                                                            

                                    

                                        19"
                                    

                                

                                                            

                                    

                                        20"
                                    

                                

                                                            

                                    

                                        22"
                                    

                                

                                                            

                                    

                                        23"
                                    

                                

                                                            

                                    

                                        24"
                                    

                                

                                            

                

                    

                                                    

                                

                                    
Tire Size

                                    
Diameter

                                    
Width

                                    
Sidewall

                                    
Circumference

                                    
Revs per mile

                                    

                                

                                                                
305/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,2"
-2.84%
12,0"
3,6"
88,6"
715
265/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,3"
-2.47%
10,4"
3,7"
88,9"
713
315/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,4"
-2.11%
12,4"
3,7"
89,3"
710
275/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,6"
-1.4%
10,8"
3,8"
89,7"
706
325/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,7"
-1.05%
12,8"
3,8"
90,0"
704
245/40R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,7"
-1.05%
9,6"
3,9"
90,2"
703
335/30R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,9"
-0.35%
13,2"
4,0"
90,8"
698

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
285/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
28,9"
-0.35%
11,2"
3,9"
90,6"
699

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
255/40R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,0"
0%
10,0"
4,0"
91,2"
695

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
295/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,1"
0.34%
11,6"
4,1"
91,5"
693

                                                    
                                                        
                                                            
                                                                
                                                                
                                                            
                                                        
                                                    
                                                Best fit
235/45R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,3"
1.02%
9,3"
4,2"
92,1"
688
265/40R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,3"
1.02%
10,4"
4,2"
92,1"
688
305/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,4"
1.36%
12,0"
4,2"
92,3"
686
275/40R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,7"
2.36%
10,8"
4,3"
93,1"
680
245/45R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,7"
2.36%
9,6"
4,3"
93,2"
680
315/35R21
                                                
                                                    
                                                        
                                                            
                                                            
                                                            
                                                            
                                                        
                                                    
                                                
                                            
29,7"
2.36%
12,4"
4,3"
93,2"
680