| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 305/80-18 | -0.61 % | 49.70 | 1,006.10 | 37.21 | 9.61 | 244.00 |
| 325/75-18 | -0.66 % | 49.67 | 1,006.62 | 37.19 | 9.60 | 243.75 |
| 295/85-18 | +0.81 % | 50.40 | 991.90 | 37.74 | 9.87 | 250.75 |
| 335/75-18 | +0.91 % | 50.46 | 990.85 | 37.78 | 9.89 | 251.25 |
| 285/85-18 | -0.98 % | 49.51 | 1,009.78 | 37.07 | 9.54 | 242.25 |
| 315/80-18 | +1.07 % | 50.54 | 989.27 | 37.84 | 9.92 | 252.00 |
| Ratio: | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Wheel Size 12
|
|||||||||||||
|
Wheel Size 13
|
|||||||||||||
|
Wheel Size 14
|
|||||||||||||
|
Wheel Size 15
|
|||||||||||||
|
Wheel Size 16
|
|||||||||||||
|
Wheel Size 16.5
|
|||||||||||||
|
Wheel Size 17
|
|||||||||||||
|
Wheel Size 18
|
|||||||||||||
| 145 |
145/25-18
d=20.85
w=1.43
-44.30%
|
145/30-18
d=21.43
w=1.71
-42.78%
|
145/35-18
d=22.00
w=2.00
-41.25%
|
145/40-18
d=22.57
w=2.28
-39.73%
|
145/45-18
d=23.14
w=2.57
-38.20%
|
145/50-18
d=23.71
w=2.85
-36.68%
|
145/55-18
d=24.28
w=3.14
-35.15%
|
145/60-18
d=24.85
w=3.43
-33.63%
|
145/65-18
d=25.42
w=3.71
-32.10%
|
145/70-18
d=25.99
w=4.00
-30.58%
|
145/75-18
d=26.56
w=4.28
-29.05%
|
145/80-18
d=27.13
w=4.57
-27.53%
|
145/85-18
d=27.70
w=4.85
-26.00%
|
| 155 |
155/25-18
d=21.05
w=1.53
-43.77%
|
155/30-18
d=21.66
w=1.83
-42.15%
|
155/35-18
d=22.27
w=2.14
-40.52%
|
155/40-18
d=22.88
w=2.44
-38.89%
|
155/45-18
d=23.49
w=2.75
-37.26%
|
155/50-18
d=24.10
w=3.05
-35.63%
|
155/55-18
d=24.71
w=3.36
-34.00%
|
155/60-18
d=25.32
w=3.66
-32.37%
|
155/65-18
d=25.93
w=3.97
-30.74%
|
155/70-18
d=26.54
w=4.27
-29.11%
|
155/75-18
d=27.15
w=4.58
-27.48%
|
155/80-18
d=27.76
w=4.88
-25.85%
|
155/85-18
d=28.37
w=5.19
-24.22%
|
| 165 |
165/25-18
d=21.25
w=1.62
-43.25%
|
165/30-18
d=21.90
w=1.95
-41.51%
|
165/35-18
d=22.55
w=2.27
-39.78%
|
165/40-18
d=23.20
w=2.60
-38.04%
|
165/45-18
d=23.85
w=2.92
-36.31%
|
165/50-18
d=24.50
w=3.25
-34.57%
|
165/55-18
d=25.15
w=3.57
-32.84%
|
165/60-18
d=25.80
w=3.90
-31.10%
|
165/65-18
d=26.44
w=4.22
-29.37%
|
165/70-18
d=27.09
w=4.55
-27.63%
|
165/75-18
d=27.74
w=4.87
-25.90%
|
165/80-18
d=28.39
w=5.20
-24.16%
|
165/85-18
d=29.04
w=5.52
-22.43%
|
| 175 |
175/25-18
d=21.44
w=1.72
-42.72%
|
175/30-18
d=22.13
w=2.07
-40.88%
|
175/35-18
d=22.82
w=2.41
-39.04%
|
175/40-18
d=23.51
w=2.76
-37.20%
|
175/45-18
d=24.20
w=3.10
-35.36%
|
175/50-18
d=24.89
w=3.44
-33.52%
|
175/55-18
d=25.58
w=3.79
-31.68%
|
175/60-18
d=26.27
w=4.13
-29.84%
|
175/65-18
d=26.96
w=4.48
-28.00%
|
175/70-18
d=27.65
w=4.82
-26.16%
|
175/75-18
d=28.33
w=5.17
-24.32%
|
175/80-18
d=29.02
w=5.51
-22.48%
|
175/85-18
d=29.71
w=5.86
-20.64%
|
| 185 |
185/25-18
d=21.64
w=1.82
-42.20%
|
185/30-18
d=22.37
w=2.19
-40.25%
|
185/35-18
d=23.10
w=2.55
-38.31%
|
185/40-18
d=23.83
w=2.91
-36.36%
|
185/45-18
d=24.56
w=3.28
-34.42%
|
185/50-18
d=25.28
w=3.64
-32.47%
|
185/55-18
d=26.01
w=4.01
-30.53%
|
185/60-18
d=26.74
w=4.37
-28.58%
|
185/65-18
d=27.47
w=4.73
-26.64%
|
185/70-18
d=28.20
w=5.10
-24.69%
|
185/75-18
d=28.93
w=5.46
-22.74%
|
185/80-18
d=29.65
w=5.83
-20.80%
|
185/85-18
d=30.38
w=6.19
-18.85%
|
| 195 |
195/25-18
d=21.84
w=1.92
-41.67%
|
195/30-18
d=22.61
w=2.30
-39.62%
|
195/35-18
d=23.37
w=2.69
-37.57%
|
195/40-18
d=24.14
w=3.07
-35.52%
|
195/45-18
d=24.91
w=3.45
-33.47%
|
195/50-18
d=25.68
w=3.84
-31.42%
|
195/55-18
d=26.44
w=4.22
-29.37%
|
195/60-18
d=27.21
w=4.61
-27.32%
|
195/65-18
d=27.98
w=4.99
-25.27%
|
195/70-18
d=28.75
w=5.37
-23.22%
|
195/75-18
d=29.52
w=5.76
-21.17%
|
195/80-18
d=30.28
w=6.14
-19.12%
|
195/85-18
d=31.05
w=6.53
-17.07%
|
| 205 |
205/25-18
d=22.04
w=2.02
-41.15%
|
205/30-18
d=22.84
w=2.42
-38.99%
|
205/35-18
d=23.65
w=2.82
-36.83%
|
205/40-18
d=24.46
w=3.23
-34.68%
|
205/45-18
d=25.26
w=3.63
-32.52%
|
205/50-18
d=26.07
w=4.04
-30.37%
|
205/55-18
d=26.88
w=4.44
-28.21%
|
205/60-18
d=27.69
w=4.84
-26.06%
|
205/65-18
d=28.49
w=5.25
-23.90%
|
205/70-18
d=29.30
w=5.65
-21.75%
|
205/75-18
d=30.11
w=6.05
-19.59%
|
205/80-18
d=30.91
w=6.46
-17.43%
|
205/85-18
d=31.72
w=6.86
-15.28%
|
| 215 |
215/25-18
d=22.23
w=2.12
-40.62%
|
215/30-18
d=23.08
w=2.54
-38.36%
|
215/35-18
d=23.93
w=2.96
-36.10%
|
215/40-18
d=24.77
w=3.39
-33.84%
|
215/45-18
d=25.62
w=3.81
-31.58%
|
215/50-18
d=26.46
w=4.23
-29.32%
|
215/55-18
d=27.31
w=4.66
-27.06%
|
215/60-18
d=28.16
w=5.08
-24.79%
|
215/65-18
d=29.00
w=5.50
-22.53%
|
215/70-18
d=29.85
w=5.93
-20.27%
|
215/75-18
d=30.70
w=6.35
-18.01%
|
215/80-18
d=31.54
w=6.77
-15.75%
|
215/85-18
d=32.39
w=7.19
-13.49%
|
| 225 |
225/25-18
d=22.43
w=2.21
-40.09%
|
225/30-18
d=23.31
w=2.66
-37.73%
|
225/35-18
d=24.20
w=3.10
-35.36%
|
225/40-18
d=25.09
w=3.54
-33.00%
|
225/45-18
d=25.97
w=3.99
-30.63%
|
225/50-18
d=26.86
w=4.43
-28.26%
|
225/55-18
d=27.74
w=4.87
-25.90%
|
225/60-18
d=28.63
w=5.31
-23.53%
|
225/65-18
d=29.52
w=5.76
-21.17%
|
225/70-18
d=30.40
w=6.20
-18.80%
|
225/75-18
d=31.29
w=6.64
-16.44%
|
225/80-18
d=32.17
w=7.09
-14.07%
|
225/85-18
d=33.06
w=7.53
-11.70%
|
| 235 |
235/25-18
d=22.63
w=2.31
-39.57%
|
235/30-18
d=23.55
w=2.78
-37.10%
|
235/35-18
d=24.48
w=3.24
-34.63%
|
235/40-18
d=25.40
w=3.70
-32.16%
|
235/45-18
d=26.33
w=4.16
-29.68%
|
235/50-18
d=27.25
w=4.63
-27.21%
|
235/55-18
d=28.18
w=5.09
-24.74%
|
235/60-18
d=29.10
w=5.55
-22.27%
|
235/65-18
d=30.03
w=6.01
-19.80%
|
235/70-18
d=30.95
w=6.48
-17.33%
|
235/75-18
d=31.88
w=6.94
-14.86%
|
235/80-18
d=32.80
w=7.40
-12.39%
|
235/85-18
d=33.73
w=7.86
-9.92%
|
| 245 |
245/25-18
d=22.82
w=2.41
-39.04%
|
245/30-18
d=23.79
w=2.89
-36.47%
|
245/35-18
d=24.75
w=3.38
-33.89%
|
245/40-18
d=25.72
w=3.86
-31.31%
|
245/45-18
d=26.68
w=4.34
-28.74%
|
245/50-18
d=27.65
w=4.82
-26.16%
|
245/55-18
d=28.61
w=5.31
-23.59%
|
245/60-18
d=29.57
w=5.79
-21.01%
|
245/65-18
d=30.54
w=6.27
-18.43%
|
245/70-18
d=31.50
w=6.75
-15.86%
|
245/75-18
d=32.47
w=7.23
-13.28%
|
245/80-18
d=33.43
w=7.72
-10.70%
|
245/85-18
d=34.40
w=8.20
-8.13%
|
| 255 |
255/25-18
d=23.02
w=2.51
-38.52%
|
255/30-18
d=24.02
w=3.01
-35.84%
|
255/35-18
d=25.03
w=3.51
-33.15%
|
255/40-18
d=26.03
w=4.02
-30.47%
|
255/45-18
d=27.04
w=4.52
-27.79%
|
255/50-18
d=28.04
w=5.02
-25.11%
|
255/55-18
d=29.04
w=5.52
-22.43%
|
255/60-18
d=30.05
w=6.02
-19.75%
|
255/65-18
d=31.05
w=6.53
-17.07%
|
255/70-18
d=32.06
w=7.03
-14.38%
|
255/75-18
d=33.06
w=7.53
-11.70%
|
255/80-18
d=34.06
w=8.03
-9.02%
|
255/85-18
d=35.07
w=8.53
-6.34%
|
| 265 |
265/25-18
d=23.22
w=2.61
-37.99%
|
265/30-18
d=24.26
w=3.13
-35.21%
|
265/35-18
d=25.30
w=3.65
-32.42%
|
265/40-18
d=26.35
w=4.17
-29.63%
|
265/45-18
d=27.39
w=4.69
-26.85%
|
265/50-18
d=28.43
w=5.22
-24.06%
|
265/55-18
d=29.48
w=5.74
-21.27%
|
265/60-18
d=30.52
w=6.26
-18.49%
|
265/65-18
d=31.56
w=6.78
-15.70%
|
265/70-18
d=32.61
w=7.30
-12.91%
|
265/75-18
d=33.65
w=7.82
-10.13%
|
265/80-18
d=34.69
w=8.35
-7.34%
|
265/85-18
d=35.74
w=8.87
-4.55%
|
| 275 |
275/25-18
d=23.41
w=2.71
-37.47%
|
275/30-18
d=24.50
w=3.25
-34.57%
|
275/35-18
d=25.58
w=3.79
-31.68%
|
275/40-18
d=26.66
w=4.33
-28.79%
|
275/45-18
d=27.74
w=4.87
-25.90%
|
275/50-18
d=28.83
w=5.41
-23.01%
|
275/55-18
d=29.91
w=5.95
-20.12%
|
275/60-18
d=30.99
w=6.50
-17.22%
|
275/65-18
d=32.07
w=7.04
-14.33%
|
275/70-18
d=33.16
w=7.58
-11.44%
|
275/75-18
d=34.24
w=8.12
-8.55%
|
275/80-18
d=35.32
w=8.66
-5.66%
|
275/85-18
d=36.41
w=9.20
-2.77%
|
| 285 |
285/25-18
d=23.61
w=2.81
-36.94%
|
285/30-18
d=24.73
w=3.37
-33.94%
|
285/35-18
d=25.85
w=3.93
-30.95%
|
285/40-18
d=26.98
w=4.49
-27.95%
|
285/45-18
d=28.10
w=5.05
-24.95%
|
285/50-18
d=29.22
w=5.61
-21.96%
|
285/55-18
d=30.34
w=6.17
-18.96%
|
285/60-18
d=31.46
w=6.73
-15.96%
|
285/65-18
d=32.59
w=7.29
-12.97%
|
285/70-18
d=33.71
w=7.85
-9.97%
|
285/75-18
d=34.83
w=8.42
-6.97%
|
285/80-18
d=35.95
w=8.98
-3.97%
|
285/85-18
d=37.07
w=9.54
-0.98%
|
| 295 |
295/25-18
d=23.81
w=2.90
-36.41%
|
295/30-18
d=24.97
w=3.48
-33.31%
|
295/35-18
d=26.13
w=4.06
-30.21%
|
295/40-18
d=27.29
w=4.65
-27.11%
|
295/45-18
d=28.45
w=5.23
-24.01%
|
295/50-18
d=29.61
w=5.81
-20.90%
|
295/55-18
d=30.78
w=6.39
-17.80%
|
295/60-18
d=31.94
w=6.97
-14.70%
|
295/65-18
d=33.10
w=7.55
-11.60%
|
295/70-18
d=34.26
w=8.13
-8.50%
|
295/75-18
d=35.42
w=8.71
-5.39%
|
295/80-18
d=36.58
w=9.29
-2.29%
|
295/85-18
d=37.74
w=9.87
+0.81%
|
| 305 |
305/25-18
d=24.00
w=3.00
-35.89%
|
305/30-18
d=25.20
w=3.60
-32.68%
|
305/35-18
d=26.41
w=4.20
-29.47%
|
305/40-18
d=27.61
w=4.80
-26.27%
|
305/45-18
d=28.81
w=5.40
-23.06%
|
305/50-18
d=30.01
w=6.00
-19.85%
|
305/55-18
d=31.21
w=6.60
-16.65%
|
305/60-18
d=32.41
w=7.20
-13.44%
|
305/65-18
d=33.61
w=7.81
-10.23%
|
305/70-18
d=34.81
w=8.41
-7.02%
|
305/75-18
d=36.01
w=9.01
-3.82%
|
305/80-18
d=37.21
w=9.61
-0.61%
|
305/85-18
d=38.41
w=10.21
+2.60%
|
| 315 |
315/25-18
d=24.20
w=3.10
-35.36%
|
315/30-18
d=25.44
w=3.72
-32.05%
|
315/35-18
d=26.68
w=4.34
-28.74%
|
315/40-18
d=27.92
w=4.96
-25.43%
|
315/45-18
d=29.16
w=5.58
-22.11%
|
315/50-18
d=30.40
w=6.20
-18.80%
|
315/55-18
d=31.64
w=6.82
-15.49%
|
315/60-18
d=32.88
w=7.44
-12.18%
|
315/65-18
d=34.12
w=8.06
-8.86%
|
315/70-18
d=35.36
w=8.68
-5.55%
|
315/75-18
d=36.60
w=9.30
-2.24%
|
315/80-18
d=37.84
w=9.92
+1.07%
|
315/85-18
d=39.08
w=10.54
+4.38%
|
| 325 |
325/25-18
d=24.40
w=3.20
-34.84%
|
325/30-18
d=25.68
w=3.84
-31.42%
|
325/35-18
d=26.96
w=4.48
-28.00%
|
325/40-18
d=28.24
w=5.12
-24.58%
|
325/45-18
d=29.52
w=5.76
-21.17%
|
325/50-18
d=30.80
w=6.40
-17.75%
|
325/55-18
d=32.07
w=7.04
-14.33%
|
325/60-18
d=33.35
w=7.68
-10.91%
|
325/65-18
d=34.63
w=8.32
-7.50%
|
325/70-18
d=35.91
w=8.96
-4.08%
|
325/75-18
d=37.19
w=9.60
-0.66%
|
325/80-18
d=38.47
w=10.24
+2.75%
|
325/85-18
d=39.75
w=10.88
+6.17%
|
| 335 |
335/25-18
d=24.59
w=3.30
-34.31%
|
335/30-18
d=25.91
w=3.96
-30.79%
|
335/35-18
d=27.23
w=4.62
-27.27%
|
335/40-18
d=28.55
w=5.28
-23.74%
|
335/45-18
d=29.87
w=5.94
-20.22%
|
335/50-18
d=31.19
w=6.59
-16.70%
|
335/55-18
d=32.51
w=7.25
-13.18%
|
335/60-18
d=33.83
w=7.91
-9.65%
|
335/65-18
d=35.15
w=8.57
-6.13%
|
335/70-18
d=36.46
w=9.23
-2.61%
|
335/75-18
d=37.78
w=9.89
+0.91%
|
335/80-18
d=39.10
w=10.55
+4.44%
|
335/85-18
d=40.42
w=11.21
+7.96%
|
|
Wheel Size 19
|
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|
Wheel Size 20
|
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|
Wheel Size 21
|
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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!