| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 245/55-21 | +0.01 % | 50.01 | 999.88 | 31.61 | 5.31 | 134.75 |
| 225/60-21 | +0.07 % | 50.04 | 999.25 | 31.63 | 5.31 | 135.00 |
| 335/40-21 | -0.17 % | 49.91 | 1,001.74 | 31.55 | 5.28 | 134.00 |
| 205/65-21 | -0.36 % | 49.82 | 1,003.61 | 31.49 | 5.25 | 133.25 |
| 195/70-21 | +0.45 % | 50.22 | 995.52 | 31.75 | 5.37 | 136.50 |
| 295/45-21 | -0.49 % | 49.76 | 1,004.86 | 31.45 | 5.23 | 132.75 |
| 265/50-21 | -0.55 % | 49.73 | 1,005.48 | 31.43 | 5.22 | 132.50 |
| 305/45-21 | +0.64 % | 50.32 | 993.65 | 31.81 | 5.40 | 137.25 |
| 165/80-21 | -0.67 % | 49.66 | 1,006.73 | 31.39 | 5.20 | 132.00 |
| 275/50-21 | +0.70 % | 50.35 | 993.02 | 31.83 | 5.41 | 137.50 |
| 155/85-21 | -0.73 % | 49.63 | 1,007.35 | 31.37 | 5.19 | 131.75 |
| 175/75-21 | -0.86 % | 49.57 | 1,008.59 | 31.33 | 5.17 | 131.25 |
| 185/75-21 | +1.01 % | 50.50 | 989.91 | 31.93 | 5.46 | 138.75 |
| 325/40-21 | -1.17 % | 49.41 | 1,011.71 | 31.24 | 5.12 | 130.00 |
| 215/65-21 | +1.26 % | 50.63 | 987.42 | 32.00 | 5.50 | 139.75 |
| 185/70-21 | -1.30 % | 49.35 | 1,012.95 | 31.20 | 5.10 | 129.50 |
| 175/80-21 | +1.32 % | 50.66 | 986.80 | 32.02 | 5.51 | 140.00 |
| 235/55-21 | -1.36 % | 49.32 | 1,013.58 | 31.18 | 5.09 | 129.25 |
| 255/55-21 | +1.38 % | 50.69 | 986.17 | 32.04 | 5.52 | 140.25 |
| 165/85-21 | +1.38 % | 50.69 | 986.17 | 32.04 | 5.52 | 140.25 |
| 215/60-21 | -1.42 % | 49.29 | 1,014.20 | 31.16 | 5.08 | 129.00 |
| 235/60-21 | +1.57 % | 50.78 | 984.30 | 32.10 | 5.55 | 141.00 |
| 285/45-21 | -1.61 % | 49.20 | 1,016.07 | 31.10 | 5.05 | 128.25 |
| 315/45-21 | +1.76 % | 50.88 | 982.44 | 32.16 | 5.58 | 141.75 |
| 255/50-21 | -1.79 % | 49.10 | 1,017.94 | 31.04 | 5.02 | 127.50 |
| 285/50-21 | +1.94 % | 50.97 | 980.57 | 32.22 | 5.61 | 142.50 |
| 195/65-21 | -1.98 % | 49.01 | 1,019.81 | 30.98 | 4.99 | 126.75 |
| Ratio: | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Wheel Size 12
|
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|
Wheel Size 13
|
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|
Wheel Size 14
|
|||||||||||||
|
Wheel Size 15
|
|||||||||||||
|
Wheel Size 16
|
|||||||||||||
|
Wheel Size 16.5
|
|||||||||||||
|
Wheel Size 17
|
|||||||||||||
|
Wheel Size 18
|
|||||||||||||
|
Wheel Size 19
|
|||||||||||||
|
Wheel Size 20
|
|||||||||||||
|
Wheel Size 21
|
|||||||||||||
| 145 |
145/25-21
d=23.85
w=1.43
-24.53%
|
145/30-21
d=24.43
w=1.71
-22.72%
|
145/35-21
d=25.00
w=2.00
-20.91%
|
145/40-21
d=25.57
w=2.28
-19.11%
|
145/45-21
d=26.14
w=2.57
-17.30%
|
145/50-21
d=26.71
w=2.85
-15.50%
|
145/55-21
d=27.28
w=3.14
-13.69%
|
145/60-21
d=27.85
w=3.43
-11.88%
|
145/65-21
d=28.42
w=3.71
-10.08%
|
145/70-21
d=28.99
w=4.00
-8.27%
|
145/75-21
d=29.56
w=4.28
-6.46%
|
145/80-21
d=30.13
w=4.57
-4.66%
|
145/85-21
d=30.70
w=4.85
-2.85%
|
| 155 |
155/25-21
d=24.05
w=1.53
-23.90%
|
155/30-21
d=24.66
w=1.83
-21.97%
|
155/35-21
d=25.27
w=2.14
-20.04%
|
155/40-21
d=25.88
w=2.44
-18.11%
|
155/45-21
d=26.49
w=2.75
-16.18%
|
155/50-21
d=27.10
w=3.05
-14.25%
|
155/55-21
d=27.71
w=3.36
-12.32%
|
155/60-21
d=28.32
w=3.66
-10.39%
|
155/65-21
d=28.93
w=3.97
-8.46%
|
155/70-21
d=29.54
w=4.27
-6.53%
|
155/75-21
d=30.15
w=4.58
-4.60%
|
155/80-21
d=30.76
w=4.88
-2.67%
|
155/85-21
d=31.37
w=5.19
-0.73%
|
| 165 |
165/25-21
d=24.25
w=1.62
-23.28%
|
165/30-21
d=24.90
w=1.95
-21.23%
|
165/35-21
d=25.55
w=2.27
-19.17%
|
165/40-21
d=26.20
w=2.60
-17.12%
|
165/45-21
d=26.85
w=2.92
-15.06%
|
165/50-21
d=27.50
w=3.25
-13.00%
|
165/55-21
d=28.15
w=3.57
-10.95%
|
165/60-21
d=28.80
w=3.90
-8.89%
|
165/65-21
d=29.44
w=4.22
-6.84%
|
165/70-21
d=30.09
w=4.55
-4.78%
|
165/75-21
d=30.74
w=4.87
-2.73%
|
165/80-21
d=31.39
w=5.20
-0.67%
|
165/85-21
d=32.04
w=5.52
+1.38%
|
| 175 |
175/25-21
d=24.44
w=1.72
-22.66%
|
175/30-21
d=25.13
w=2.07
-20.48%
|
175/35-21
d=25.82
w=2.41
-18.30%
|
175/40-21
d=26.51
w=2.76
-16.12%
|
175/45-21
d=27.20
w=3.10
-13.94%
|
175/50-21
d=27.89
w=3.44
-11.76%
|
175/55-21
d=28.58
w=3.79
-9.58%
|
175/60-21
d=29.27
w=4.13
-7.40%
|
175/65-21
d=29.96
w=4.48
-5.22%
|
175/70-21
d=30.65
w=4.82
-3.04%
|
175/75-21
d=31.33
w=5.17
-0.86%
|
175/80-21
d=32.02
w=5.51
+1.32%
|
175/85-21
d=32.71
w=5.86
+3.50%
|
| 185 |
185/25-21
d=24.64
w=1.82
-22.04%
|
185/30-21
d=25.37
w=2.19
-19.73%
|
185/35-21
d=26.10
w=2.55
-17.43%
|
185/40-21
d=26.83
w=2.91
-15.12%
|
185/45-21
d=27.56
w=3.28
-12.82%
|
185/50-21
d=28.28
w=3.64
-10.51%
|
185/55-21
d=29.01
w=4.01
-8.21%
|
185/60-21
d=29.74
w=4.37
-5.90%
|
185/65-21
d=30.47
w=4.73
-3.60%
|
185/70-21
d=31.20
w=5.10
-1.30%
|
185/75-21
d=31.93
w=5.46
+1.01%
|
185/80-21
d=32.65
w=5.83
+3.31%
|
185/85-21
d=33.38
w=6.19
+5.62%
|
| 195 |
195/25-21
d=24.84
w=1.92
-21.41%
|
195/30-21
d=25.61
w=2.30
-18.98%
|
195/35-21
d=26.37
w=2.69
-16.55%
|
195/40-21
d=27.14
w=3.07
-14.13%
|
195/45-21
d=27.91
w=3.45
-11.70%
|
195/50-21
d=28.68
w=3.84
-9.27%
|
195/55-21
d=29.44
w=4.22
-6.84%
|
195/60-21
d=30.21
w=4.61
-4.41%
|
195/65-21
d=30.98
w=4.99
-1.98%
|
195/70-21
d=31.75
w=5.37
+0.45%
|
195/75-21
d=32.52
w=5.76
+2.88%
|
195/80-21
d=33.28
w=6.14
+5.31%
|
195/85-21
d=34.05
w=6.53
+7.74%
|
| 205 |
205/25-21
d=25.04
w=2.02
-20.79%
|
205/30-21
d=25.84
w=2.42
-18.24%
|
205/35-21
d=26.65
w=2.82
-15.68%
|
205/40-21
d=27.46
w=3.23
-13.13%
|
205/45-21
d=28.26
w=3.63
-10.58%
|
205/50-21
d=29.07
w=4.04
-8.02%
|
205/55-21
d=29.88
w=4.44
-5.47%
|
205/60-21
d=30.69
w=4.84
-2.91%
|
205/65-21
d=31.49
w=5.25
-0.36%
|
205/70-21
d=32.30
w=5.65
+2.19%
|
205/75-21
d=33.11
w=6.05
+4.75%
|
205/80-21
d=33.91
w=6.46
+7.30%
|
205/85-21
d=34.72
w=6.86
+9.85%
|
| 215 |
215/25-21
d=25.23
w=2.12
-20.17%
|
215/30-21
d=26.08
w=2.54
-17.49%
|
215/35-21
d=26.93
w=2.96
-14.81%
|
215/40-21
d=27.77
w=3.39
-12.13%
|
215/45-21
d=28.62
w=3.81
-9.45%
|
215/50-21
d=29.46
w=4.23
-6.78%
|
215/55-21
d=30.31
w=4.66
-4.10%
|
215/60-21
d=31.16
w=5.08
-1.42%
|
215/65-21
d=32.00
w=5.50
+1.26%
|
215/70-21
d=32.85
w=5.93
+3.94%
|
215/75-21
d=33.70
w=6.35
+6.61%
|
215/80-21
d=34.54
w=6.77
+9.29%
|
215/85-21
d=35.39
w=7.19
+11.97%
|
| 225 |
225/25-21
d=25.43
w=2.21
-19.54%
|
225/30-21
d=26.31
w=2.66
-16.74%
|
225/35-21
d=27.20
w=3.10
-13.94%
|
225/40-21
d=28.09
w=3.54
-11.14%
|
225/45-21
d=28.97
w=3.99
-8.33%
|
225/50-21
d=29.86
w=4.43
-5.53%
|
225/55-21
d=30.74
w=4.87
-2.73%
|
225/60-21
d=31.63
w=5.31
+0.07%
|
225/65-21
d=32.52
w=5.76
+2.88%
|
225/70-21
d=33.40
w=6.20
+5.68%
|
225/75-21
d=34.29
w=6.64
+8.48%
|
225/80-21
d=35.17
w=7.09
+11.29%
|
225/85-21
d=36.06
w=7.53
+14.09%
|
| 235 |
235/25-21
d=25.63
w=2.31
-18.92%
|
235/30-21
d=26.55
w=2.78
-15.99%
|
235/35-21
d=27.48
w=3.24
-13.07%
|
235/40-21
d=28.40
w=3.70
-10.14%
|
235/45-21
d=29.33
w=4.16
-7.21%
|
235/50-21
d=30.25
w=4.63
-4.29%
|
235/55-21
d=31.18
w=5.09
-1.36%
|
235/60-21
d=32.10
w=5.55
+1.57%
|
235/65-21
d=33.03
w=6.01
+4.50%
|
235/70-21
d=33.95
w=6.48
+7.42%
|
235/75-21
d=34.88
w=6.94
+10.35%
|
235/80-21
d=35.80
w=7.40
+13.28%
|
235/85-21
d=36.73
w=7.86
+16.21%
|
| 245 |
245/25-21
d=25.82
w=2.41
-18.30%
|
245/30-21
d=26.79
w=2.89
-15.25%
|
245/35-21
d=27.75
w=3.38
-12.19%
|
245/40-21
d=28.72
w=3.86
-9.14%
|
245/45-21
d=29.68
w=4.34
-6.09%
|
245/50-21
d=30.65
w=4.82
-3.04%
|
245/55-21
d=31.61
w=5.31
+0.01%
|
245/60-21
d=32.57
w=5.79
+3.06%
|
245/65-21
d=33.54
w=6.27
+6.12%
|
245/70-21
d=34.50
w=6.75
+9.17%
|
245/75-21
d=35.47
w=7.23
+12.22%
|
245/80-21
d=36.43
w=7.72
+15.27%
|
245/85-21
d=37.40
w=8.20
+18.32%
|
| 255 |
255/25-21
d=26.02
w=2.51
-17.68%
|
255/30-21
d=27.02
w=3.01
-14.50%
|
255/35-21
d=28.03
w=3.51
-11.32%
|
255/40-21
d=29.03
w=4.02
-8.15%
|
255/45-21
d=30.04
w=4.52
-4.97%
|
255/50-21
d=31.04
w=5.02
-1.79%
|
255/55-21
d=32.04
w=5.52
+1.38%
|
255/60-21
d=33.05
w=6.02
+4.56%
|
255/65-21
d=34.05
w=6.53
+7.74%
|
255/70-21
d=35.06
w=7.03
+10.91%
|
255/75-21
d=36.06
w=7.53
+14.09%
|
255/80-21
d=37.06
w=8.03
+17.26%
|
255/85-21
d=38.07
w=8.53
+20.44%
|
| 265 |
265/25-21
d=26.22
w=2.61
-17.05%
|
265/30-21
d=27.26
w=3.13
-13.75%
|
265/35-21
d=28.30
w=3.65
-10.45%
|
265/40-21
d=29.35
w=4.17
-7.15%
|
265/45-21
d=30.39
w=4.69
-3.85%
|
265/50-21
d=31.43
w=5.22
-0.55%
|
265/55-21
d=32.48
w=5.74
+2.75%
|
265/60-21
d=33.52
w=6.26
+6.05%
|
265/65-21
d=34.56
w=6.78
+9.35%
|
265/70-21
d=35.61
w=7.30
+12.66%
|
265/75-21
d=36.65
w=7.82
+15.96%
|
265/80-21
d=37.69
w=8.35
+19.26%
|
265/85-21
d=38.74
w=8.87
+22.56%
|
| 275 |
275/25-21
d=26.41
w=2.71
-16.43%
|
275/30-21
d=27.50
w=3.25
-13.00%
|
275/35-21
d=28.58
w=3.79
-9.58%
|
275/40-21
d=29.66
w=4.33
-6.15%
|
275/45-21
d=30.74
w=4.87
-2.73%
|
275/50-21
d=31.83
w=5.41
+0.70%
|
275/55-21
d=32.91
w=5.95
+4.12%
|
275/60-21
d=33.99
w=6.50
+7.55%
|
275/65-21
d=35.07
w=7.04
+10.97%
|
275/70-21
d=36.16
w=7.58
+14.40%
|
275/75-21
d=37.24
w=8.12
+17.83%
|
275/80-21
d=38.32
w=8.66
+21.25%
|
275/85-21
d=39.41
w=9.20
+24.68%
|
| 285 |
285/25-21
d=26.61
w=2.81
-15.81%
|
285/30-21
d=27.73
w=3.37
-12.26%
|
285/35-21
d=28.85
w=3.93
-8.71%
|
285/40-21
d=29.98
w=4.49
-5.16%
|
285/45-21
d=31.10
w=5.05
-1.61%
|
285/50-21
d=32.22
w=5.61
+1.94%
|
285/55-21
d=33.34
w=6.17
+5.49%
|
285/60-21
d=34.46
w=6.73
+9.04%
|
285/65-21
d=35.59
w=7.29
+12.59%
|
285/70-21
d=36.71
w=7.85
+16.14%
|
285/75-21
d=37.83
w=8.42
+19.69%
|
285/80-21
d=38.95
w=8.98
+23.24%
|
285/85-21
d=40.07
w=9.54
+26.79%
|
| 295 |
295/25-21
d=26.81
w=2.90
-15.18%
|
295/30-21
d=27.97
w=3.48
-11.51%
|
295/35-21
d=29.13
w=4.06
-7.84%
|
295/40-21
d=30.29
w=4.65
-4.16%
|
295/45-21
d=31.45
w=5.23
-0.49%
|
295/50-21
d=32.61
w=5.81
+3.19%
|
295/55-21
d=33.78
w=6.39
+6.86%
|
295/60-21
d=34.94
w=6.97
+10.54%
|
295/65-21
d=36.10
w=7.55
+14.21%
|
295/70-21
d=37.26
w=8.13
+17.89%
|
295/75-21
d=38.42
w=8.71
+21.56%
|
295/80-21
d=39.58
w=9.29
+25.24%
|
295/85-21
d=40.74
w=9.87
+28.91%
|
| 305 |
305/25-21
d=27.00
w=3.00
-14.56%
|
305/30-21
d=28.20
w=3.60
-10.76%
|
305/35-21
d=29.41
w=4.20
-6.96%
|
305/40-21
d=30.61
w=4.80
-3.16%
|
305/45-21
d=31.81
w=5.40
+0.64%
|
305/50-21
d=33.01
w=6.00
+4.43%
|
305/55-21
d=34.21
w=6.60
+8.23%
|
305/60-21
d=35.41
w=7.20
+12.03%
|
305/65-21
d=36.61
w=7.81
+15.83%
|
305/70-21
d=37.81
w=8.41
+19.63%
|
305/75-21
d=39.01
w=9.01
+23.43%
|
305/80-21
d=40.21
w=9.61
+27.23%
|
305/85-21
d=41.41
w=10.21
+31.03%
|
| 315 |
315/25-21
d=27.20
w=3.10
-13.94%
|
315/30-21
d=28.44
w=3.72
-10.01%
|
315/35-21
d=29.68
w=4.34
-6.09%
|
315/40-21
d=30.92
w=4.96
-2.17%
|
315/45-21
d=32.16
w=5.58
+1.76%
|
315/50-21
d=33.40
w=6.20
+5.68%
|
315/55-21
d=34.64
w=6.82
+9.60%
|
315/60-21
d=35.88
w=7.44
+13.53%
|
315/65-21
d=37.12
w=8.06
+17.45%
|
315/70-21
d=38.36
w=8.68
+21.38%
|
315/75-21
d=39.60
w=9.30
+25.30%
|
315/80-21
d=40.84
w=9.92
+29.22%
|
315/85-21
d=42.08
w=10.54
+33.15%
|
| 325 |
325/25-21
d=27.40
w=3.20
-13.32%
|
325/30-21
d=28.68
w=3.84
-9.27%
|
325/35-21
d=29.96
w=4.48
-5.22%
|
325/40-21
d=31.24
w=5.12
-1.17%
|
325/45-21
d=32.52
w=5.76
+2.88%
|
325/50-21
d=33.80
w=6.40
+6.93%
|
325/55-21
d=35.07
w=7.04
+10.97%
|
325/60-21
d=36.35
w=7.68
+15.02%
|
325/65-21
d=37.63
w=8.32
+19.07%
|
325/70-21
d=38.91
w=8.96
+23.12%
|
325/75-21
d=40.19
w=9.60
+27.17%
|
325/80-21
d=41.47
w=10.24
+31.22%
|
325/85-21
d=42.75
w=10.88
+35.26%
|
| 335 |
335/25-21
d=27.59
w=3.30
-12.69%
|
335/30-21
d=28.91
w=3.96
-8.52%
|
335/35-21
d=30.23
w=4.62
-4.35%
|
335/40-21
d=31.55
w=5.28
-0.17%
|
335/45-21
d=32.87
w=5.94
+4.00%
|
335/50-21
d=34.19
w=6.59
+8.17%
|
335/55-21
d=35.51
w=7.25
+12.34%
|
335/60-21
d=36.83
w=7.91
+16.52%
|
335/65-21
d=38.15
w=8.57
+20.69%
|
335/70-21
d=39.46
w=9.23
+24.86%
|
335/75-21
d=40.78
w=9.89
+29.04%
|
335/80-21
d=42.10
w=10.55
+33.21%
|
335/85-21
d=43.42
w=11.21
+37.38%
|
The information on this page is intended to be helpful, but there is absolutely no guarantee of its accuracy, safety, or applicability for any particular use. The data is calculated mathematically, not taken from any official or recommended guide.
Please excercise a common sense, follow manufacturer and dealer recommendations, and check with other sources.
Tires are a safety equipment, don't take their selection lightly!