| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 275/70-18 | 0.00 % | 50.00 | 1,000.00 | 33.16 | 7.58 | 192.50 |
| 295/65-18 | -0.18 % | 49.91 | 1,001.78 | 33.10 | 7.55 | 191.75 |
| 255/75-18 | -0.30 % | 49.85 | 1,002.97 | 33.06 | 7.53 | 191.25 |
| 225/85-18 | -0.30 % | 49.85 | 1,002.97 | 33.06 | 7.53 | 191.25 |
| 325/60-18 | +0.59 % | 50.30 | 994.06 | 33.35 | 7.68 | 195.00 |
| 315/60-18 | -0.83 % | 49.58 | 1,008.31 | 32.88 | 7.44 | 189.00 |
| 245/80-18 | +0.83 % | 50.42 | 991.69 | 33.43 | 7.72 | 196.00 |
| 235/80-18 | -1.07 % | 49.47 | 1,010.69 | 32.80 | 7.40 | 188.00 |
| 305/65-18 | +1.37 % | 50.68 | 986.35 | 33.61 | 7.81 | 198.25 |
| 265/75-18 | +1.48 % | 50.74 | 985.16 | 33.65 | 7.82 | 198.75 |
| 265/70-18 | -1.66 % | 49.17 | 1,016.62 | 32.61 | 7.30 | 185.50 |
| 285/70-18 | +1.66 % | 50.83 | 983.38 | 33.71 | 7.85 | 199.50 |
| 285/65-18 | -1.72 % | 49.14 | 1,017.22 | 32.59 | 7.29 | 185.25 |
| 235/85-18 | +1.72 % | 50.86 | 982.78 | 33.73 | 7.86 | 199.75 |
| 335/55-18 | -1.96 % | 49.02 | 1,019.59 | 32.51 | 7.25 | 184.25 |
| 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
-37.11%
|
145/30-18
d=21.43
w=1.71
-35.38%
|
145/35-18
d=22.00
w=2.00
-33.66%
|
145/40-18
d=22.57
w=2.28
-31.94%
|
145/45-18
d=23.14
w=2.57
-30.22%
|
145/50-18
d=23.71
w=2.85
-28.50%
|
145/55-18
d=24.28
w=3.14
-26.78%
|
145/60-18
d=24.85
w=3.43
-25.05%
|
145/65-18
d=25.42
w=3.71
-23.33%
|
145/70-18
d=25.99
w=4.00
-21.61%
|
145/75-18
d=26.56
w=4.28
-19.89%
|
145/80-18
d=27.13
w=4.57
-18.17%
|
145/85-18
d=27.70
w=4.85
-16.45%
|
| 155 |
155/25-18
d=21.05
w=1.53
-36.51%
|
155/30-18
d=21.66
w=1.83
-34.67%
|
155/35-18
d=22.27
w=2.14
-32.83%
|
155/40-18
d=22.88
w=2.44
-30.99%
|
155/45-18
d=23.49
w=2.75
-29.15%
|
155/50-18
d=24.10
w=3.05
-27.31%
|
155/55-18
d=24.71
w=3.36
-25.47%
|
155/60-18
d=25.32
w=3.66
-23.63%
|
155/65-18
d=25.93
w=3.97
-21.79%
|
155/70-18
d=26.54
w=4.27
-19.95%
|
155/75-18
d=27.15
w=4.58
-18.11%
|
155/80-18
d=27.76
w=4.88
-16.27%
|
155/85-18
d=28.37
w=5.19
-14.43%
|
| 165 |
165/25-18
d=21.25
w=1.62
-35.92%
|
165/30-18
d=21.90
w=1.95
-33.96%
|
165/35-18
d=22.55
w=2.27
-32.00%
|
165/40-18
d=23.20
w=2.60
-30.04%
|
165/45-18
d=23.85
w=2.92
-28.08%
|
165/50-18
d=24.50
w=3.25
-26.12%
|
165/55-18
d=25.15
w=3.57
-24.16%
|
165/60-18
d=25.80
w=3.90
-22.20%
|
165/65-18
d=26.44
w=4.22
-20.24%
|
165/70-18
d=27.09
w=4.55
-18.29%
|
165/75-18
d=27.74
w=4.87
-16.33%
|
165/80-18
d=28.39
w=5.20
-14.37%
|
165/85-18
d=29.04
w=5.52
-12.41%
|
| 175 |
175/25-18
d=21.44
w=1.72
-35.32%
|
175/30-18
d=22.13
w=2.07
-33.25%
|
175/35-18
d=22.82
w=2.41
-31.17%
|
175/40-18
d=23.51
w=2.76
-29.09%
|
175/45-18
d=24.20
w=3.10
-27.01%
|
175/50-18
d=24.89
w=3.44
-24.93%
|
175/55-18
d=25.58
w=3.79
-22.86%
|
175/60-18
d=26.27
w=4.13
-20.78%
|
175/65-18
d=26.96
w=4.48
-18.70%
|
175/70-18
d=27.65
w=4.82
-16.62%
|
175/75-18
d=28.33
w=5.17
-14.55%
|
175/80-18
d=29.02
w=5.51
-12.47%
|
175/85-18
d=29.71
w=5.86
-10.39%
|
| 185 |
185/25-18
d=21.64
w=1.82
-34.73%
|
185/30-18
d=22.37
w=2.19
-32.53%
|
185/35-18
d=23.10
w=2.55
-30.34%
|
185/40-18
d=23.83
w=2.91
-28.14%
|
185/45-18
d=24.56
w=3.28
-25.94%
|
185/50-18
d=25.28
w=3.64
-23.75%
|
185/55-18
d=26.01
w=4.01
-21.55%
|
185/60-18
d=26.74
w=4.37
-19.35%
|
185/65-18
d=27.47
w=4.73
-17.16%
|
185/70-18
d=28.20
w=5.10
-14.96%
|
185/75-18
d=28.93
w=5.46
-12.76%
|
185/80-18
d=29.65
w=5.83
-10.57%
|
185/85-18
d=30.38
w=6.19
-8.37%
|
| 195 |
195/25-18
d=21.84
w=1.92
-34.14%
|
195/30-18
d=22.61
w=2.30
-31.82%
|
195/35-18
d=23.37
w=2.69
-29.51%
|
195/40-18
d=24.14
w=3.07
-27.19%
|
195/45-18
d=24.91
w=3.45
-24.88%
|
195/50-18
d=25.68
w=3.84
-22.56%
|
195/55-18
d=26.44
w=4.22
-20.24%
|
195/60-18
d=27.21
w=4.61
-17.93%
|
195/65-18
d=27.98
w=4.99
-15.61%
|
195/70-18
d=28.75
w=5.37
-13.30%
|
195/75-18
d=29.52
w=5.76
-10.98%
|
195/80-18
d=30.28
w=6.14
-8.67%
|
195/85-18
d=31.05
w=6.53
-6.35%
|
| 205 |
205/25-18
d=22.04
w=2.02
-33.54%
|
205/30-18
d=22.84
w=2.42
-31.11%
|
205/35-18
d=23.65
w=2.82
-28.67%
|
205/40-18
d=24.46
w=3.23
-26.24%
|
205/45-18
d=25.26
w=3.63
-23.81%
|
205/50-18
d=26.07
w=4.04
-21.37%
|
205/55-18
d=26.88
w=4.44
-18.94%
|
205/60-18
d=27.69
w=4.84
-16.50%
|
205/65-18
d=28.49
w=5.25
-14.07%
|
205/70-18
d=29.30
w=5.65
-11.64%
|
205/75-18
d=30.11
w=6.05
-9.20%
|
205/80-18
d=30.91
w=6.46
-6.77%
|
205/85-18
d=31.72
w=6.86
-4.33%
|
| 215 |
215/25-18
d=22.23
w=2.12
-32.95%
|
215/30-18
d=23.08
w=2.54
-30.40%
|
215/35-18
d=23.93
w=2.96
-27.84%
|
215/40-18
d=24.77
w=3.39
-25.29%
|
215/45-18
d=25.62
w=3.81
-22.74%
|
215/50-18
d=26.46
w=4.23
-20.19%
|
215/55-18
d=27.31
w=4.66
-17.63%
|
215/60-18
d=28.16
w=5.08
-15.08%
|
215/65-18
d=29.00
w=5.50
-12.53%
|
215/70-18
d=29.85
w=5.93
-9.97%
|
215/75-18
d=30.70
w=6.35
-7.42%
|
215/80-18
d=31.54
w=6.77
-4.87%
|
215/85-18
d=32.39
w=7.19
-2.32%
|
| 225 |
225/25-18
d=22.43
w=2.21
-32.36%
|
225/30-18
d=23.31
w=2.66
-29.68%
|
225/35-18
d=24.20
w=3.10
-27.01%
|
225/40-18
d=25.09
w=3.54
-24.34%
|
225/45-18
d=25.97
w=3.99
-21.67%
|
225/50-18
d=26.86
w=4.43
-19.00%
|
225/55-18
d=27.74
w=4.87
-16.33%
|
225/60-18
d=28.63
w=5.31
-13.65%
|
225/65-18
d=29.52
w=5.76
-10.98%
|
225/70-18
d=30.40
w=6.20
-8.31%
|
225/75-18
d=31.29
w=6.64
-5.64%
|
225/80-18
d=32.17
w=7.09
-2.97%
|
225/85-18
d=33.06
w=7.53
-0.30%
|
| 235 |
235/25-18
d=22.63
w=2.31
-31.76%
|
235/30-18
d=23.55
w=2.78
-28.97%
|
235/35-18
d=24.48
w=3.24
-26.18%
|
235/40-18
d=25.40
w=3.70
-23.39%
|
235/45-18
d=26.33
w=4.16
-20.60%
|
235/50-18
d=27.25
w=4.63
-17.81%
|
235/55-18
d=28.18
w=5.09
-15.02%
|
235/60-18
d=29.10
w=5.55
-12.23%
|
235/65-18
d=30.03
w=6.01
-9.44%
|
235/70-18
d=30.95
w=6.48
-6.65%
|
235/75-18
d=31.88
w=6.94
-3.86%
|
235/80-18
d=32.80
w=7.40
-1.07%
|
235/85-18
d=33.73
w=7.86
+1.72%
|
| 245 |
245/25-18
d=22.82
w=2.41
-31.17%
|
245/30-18
d=23.79
w=2.89
-28.26%
|
245/35-18
d=24.75
w=3.38
-25.35%
|
245/40-18
d=25.72
w=3.86
-22.44%
|
245/45-18
d=26.68
w=4.34
-19.53%
|
245/50-18
d=27.65
w=4.82
-16.62%
|
245/55-18
d=28.61
w=5.31
-13.71%
|
245/60-18
d=29.57
w=5.79
-10.81%
|
245/65-18
d=30.54
w=6.27
-7.90%
|
245/70-18
d=31.50
w=6.75
-4.99%
|
245/75-18
d=32.47
w=7.23
-2.08%
|
245/80-18
d=33.43
w=7.72
+0.83%
|
245/85-18
d=34.40
w=8.20
+3.74%
|
| 255 |
255/25-18
d=23.02
w=2.51
-30.57%
|
255/30-18
d=24.02
w=3.01
-27.55%
|
255/35-18
d=25.03
w=3.51
-24.52%
|
255/40-18
d=26.03
w=4.02
-21.49%
|
255/45-18
d=27.04
w=4.52
-18.46%
|
255/50-18
d=28.04
w=5.02
-15.44%
|
255/55-18
d=29.04
w=5.52
-12.41%
|
255/60-18
d=30.05
w=6.02
-9.38%
|
255/65-18
d=31.05
w=6.53
-6.35%
|
255/70-18
d=32.06
w=7.03
-3.32%
|
255/75-18
d=33.06
w=7.53
-0.30%
|
255/80-18
d=34.06
w=8.03
+2.73%
|
255/85-18
d=35.07
w=8.53
+5.76%
|
| 265 |
265/25-18
d=23.22
w=2.61
-29.98%
|
265/30-18
d=24.26
w=3.13
-26.83%
|
265/35-18
d=25.30
w=3.65
-23.69%
|
265/40-18
d=26.35
w=4.17
-20.54%
|
265/45-18
d=27.39
w=4.69
-17.39%
|
265/50-18
d=28.43
w=5.22
-14.25%
|
265/55-18
d=29.48
w=5.74
-11.10%
|
265/60-18
d=30.52
w=6.26
-7.96%
|
265/65-18
d=31.56
w=6.78
-4.81%
|
265/70-18
d=32.61
w=7.30
-1.66%
|
265/75-18
d=33.65
w=7.82
+1.48%
|
265/80-18
d=34.69
w=8.35
+4.63%
|
265/85-18
d=35.74
w=8.87
+7.78%
|
| 275 |
275/25-18
d=23.41
w=2.71
-29.39%
|
275/30-18
d=24.50
w=3.25
-26.12%
|
275/35-18
d=25.58
w=3.79
-22.86%
|
275/40-18
d=26.66
w=4.33
-19.59%
|
275/45-18
d=27.74
w=4.87
-16.33%
|
275/50-18
d=28.83
w=5.41
-13.06%
|
275/55-18
d=29.91
w=5.95
-9.80%
|
275/60-18
d=30.99
w=6.50
-6.53%
|
275/65-18
d=32.07
w=7.04
-3.27%
|
275/70-18
d=33.16
w=7.58
0.00%
|
275/75-18
d=34.24
w=8.12
+3.27%
|
275/80-18
d=35.32
w=8.66
+6.53%
|
275/85-18
d=36.41
w=9.20
+9.80%
|
| 285 |
285/25-18
d=23.61
w=2.81
-28.79%
|
285/30-18
d=24.73
w=3.37
-25.41%
|
285/35-18
d=25.85
w=3.93
-22.03%
|
285/40-18
d=26.98
w=4.49
-18.64%
|
285/45-18
d=28.10
w=5.05
-15.26%
|
285/50-18
d=29.22
w=5.61
-11.87%
|
285/55-18
d=30.34
w=6.17
-8.49%
|
285/60-18
d=31.46
w=6.73
-5.11%
|
285/65-18
d=32.59
w=7.29
-1.72%
|
285/70-18
d=33.71
w=7.85
+1.66%
|
285/75-18
d=34.83
w=8.42
+5.05%
|
285/80-18
d=35.95
w=8.98
+8.43%
|
285/85-18
d=37.07
w=9.54
+11.81%
|
| 295 |
295/25-18
d=23.81
w=2.90
-28.20%
|
295/30-18
d=24.97
w=3.48
-24.70%
|
295/35-18
d=26.13
w=4.06
-21.19%
|
295/40-18
d=27.29
w=4.65
-17.69%
|
295/45-18
d=28.45
w=5.23
-14.19%
|
295/50-18
d=29.61
w=5.81
-10.69%
|
295/55-18
d=30.78
w=6.39
-7.18%
|
295/60-18
d=31.94
w=6.97
-3.68%
|
295/65-18
d=33.10
w=7.55
-0.18%
|
295/70-18
d=34.26
w=8.13
+3.32%
|
295/75-18
d=35.42
w=8.71
+6.83%
|
295/80-18
d=36.58
w=9.29
+10.33%
|
295/85-18
d=37.74
w=9.87
+13.83%
|
| 305 |
305/25-18
d=24.00
w=3.00
-27.61%
|
305/30-18
d=25.20
w=3.60
-23.98%
|
305/35-18
d=26.41
w=4.20
-20.36%
|
305/40-18
d=27.61
w=4.80
-16.74%
|
305/45-18
d=28.81
w=5.40
-13.12%
|
305/50-18
d=30.01
w=6.00
-9.50%
|
305/55-18
d=31.21
w=6.60
-5.88%
|
305/60-18
d=32.41
w=7.20
-2.26%
|
305/65-18
d=33.61
w=7.81
+1.37%
|
305/70-18
d=34.81
w=8.41
+4.99%
|
305/75-18
d=36.01
w=9.01
+8.61%
|
305/80-18
d=37.21
w=9.61
+12.23%
|
305/85-18
d=38.41
w=10.21
+15.85%
|
| 315 |
315/25-18
d=24.20
w=3.10
-27.01%
|
315/30-18
d=25.44
w=3.72
-23.27%
|
315/35-18
d=26.68
w=4.34
-19.53%
|
315/40-18
d=27.92
w=4.96
-15.79%
|
315/45-18
d=29.16
w=5.58
-12.05%
|
315/50-18
d=30.40
w=6.20
-8.31%
|
315/55-18
d=31.64
w=6.82
-4.57%
|
315/60-18
d=32.88
w=7.44
-0.83%
|
315/65-18
d=34.12
w=8.06
+2.91%
|
315/70-18
d=35.36
w=8.68
+6.65%
|
315/75-18
d=36.60
w=9.30
+10.39%
|
315/80-18
d=37.84
w=9.92
+14.13%
|
315/85-18
d=39.08
w=10.54
+17.87%
|
| 325 |
325/25-18
d=24.40
w=3.20
-26.42%
|
325/30-18
d=25.68
w=3.84
-22.56%
|
325/35-18
d=26.96
w=4.48
-18.70%
|
325/40-18
d=28.24
w=5.12
-14.84%
|
325/45-18
d=29.52
w=5.76
-10.98%
|
325/50-18
d=30.80
w=6.40
-7.12%
|
325/55-18
d=32.07
w=7.04
-3.27%
|
325/60-18
d=33.35
w=7.68
+0.59%
|
325/65-18
d=34.63
w=8.32
+4.45%
|
325/70-18
d=35.91
w=8.96
+8.31%
|
325/75-18
d=37.19
w=9.60
+12.17%
|
325/80-18
d=38.47
w=10.24
+16.03%
|
325/85-18
d=39.75
w=10.88
+19.89%
|
| 335 |
335/25-18
d=24.59
w=3.30
-25.83%
|
335/30-18
d=25.91
w=3.96
-21.85%
|
335/35-18
d=27.23
w=4.62
-17.87%
|
335/40-18
d=28.55
w=5.28
-13.89%
|
335/45-18
d=29.87
w=5.94
-9.91%
|
335/50-18
d=31.19
w=6.59
-5.94%
|
335/55-18
d=32.51
w=7.25
-1.96%
|
335/60-18
d=33.83
w=7.91
+2.02%
|
335/65-18
d=35.15
w=8.57
+6.00%
|
335/70-18
d=36.46
w=9.23
+9.97%
|
335/75-18
d=37.78
w=9.89
+13.95%
|
335/80-18
d=39.10
w=10.55
+17.93%
|
335/85-18
d=40.42
w=11.21
+21.91%
|
|
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!