| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 315/30-18 | 0.00 % | 50.00 | 1,000.00 | 25.44 | 3.72 | 94.50 |
| 145/65-18 | -0.08 % | 49.96 | 1,000.77 | 25.42 | 3.71 | 94.25 |
| 235/40-18 | -0.15 % | 49.92 | 1,001.55 | 25.40 | 3.70 | 94.00 |
| 155/60-18 | -0.46 % | 49.77 | 1,004.64 | 25.32 | 3.66 | 93.00 |
| 265/35-18 | -0.54 % | 49.73 | 1,005.42 | 25.30 | 3.65 | 92.75 |
| 275/35-18 | +0.54 % | 50.27 | 994.58 | 25.58 | 3.79 | 96.25 |
| 175/55-18 | +0.54 % | 50.27 | 994.58 | 25.58 | 3.79 | 96.25 |
| 185/50-18 | -0.62 % | 49.69 | 1,006.19 | 25.28 | 3.64 | 92.50 |
| 205/45-18 | -0.70 % | 49.65 | 1,006.96 | 25.26 | 3.63 | 92.25 |
| 215/45-18 | +0.70 % | 50.35 | 993.04 | 25.62 | 3.81 | 96.75 |
| 305/30-18 | -0.93 % | 49.54 | 1,009.29 | 25.20 | 3.60 | 91.50 |
| 325/30-18 | +0.93 % | 50.46 | 990.71 | 25.68 | 3.84 | 97.50 |
| 195/50-18 | +0.93 % | 50.46 | 990.71 | 25.68 | 3.84 | 97.50 |
| 245/40-18 | +1.08 % | 50.54 | 989.17 | 25.72 | 3.86 | 98.00 |
| 165/55-18 | -1.16 % | 49.42 | 1,011.61 | 25.15 | 3.57 | 90.75 |
| 225/40-18 | -1.39 % | 49.30 | 1,013.93 | 25.09 | 3.54 | 90.00 |
| 165/60-18 | +1.39 % | 50.70 | 986.07 | 25.80 | 3.90 | 99.00 |
| 255/35-18 | -1.62 % | 49.19 | 1,016.25 | 25.03 | 3.51 | 89.25 |
| 285/35-18 | +1.62 % | 50.81 | 983.75 | 25.85 | 3.93 | 99.75 |
| 295/30-18 | -1.86 % | 49.07 | 1,018.57 | 24.97 | 3.48 | 88.50 |
| 335/30-18 | +1.86 % | 50.93 | 981.43 | 25.91 | 3.96 | 100.50 |
| 155/65-18 | +1.93 % | 50.97 | 980.66 | 25.93 | 3.97 | 100.75 |
| Ratio: | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Wheel Size 12
|
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|
Wheel Size 13
|
|||||||||||||
|
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
-18.03%
|
145/30-18
d=21.43
w=1.71
-15.78%
|
145/35-18
d=22.00
w=2.00
-13.54%
|
145/40-18
d=22.57
w=2.28
-11.30%
|
145/45-18
d=23.14
w=2.57
-9.05%
|
145/50-18
d=23.71
w=2.85
-6.81%
|
145/55-18
d=24.28
w=3.14
-4.57%
|
145/60-18
d=24.85
w=3.43
-2.32%
|
145/65-18
d=25.42
w=3.71
-0.08%
|
145/70-18
d=25.99
w=4.00
+2.17%
|
145/75-18
d=26.56
w=4.28
+4.41%
|
145/80-18
d=27.13
w=4.57
+6.65%
|
145/85-18
d=27.70
w=4.85
+8.90%
|
| 155 |
155/25-18
d=21.05
w=1.53
-17.25%
|
155/30-18
d=21.66
w=1.83
-14.86%
|
155/35-18
d=22.27
w=2.14
-12.46%
|
155/40-18
d=22.88
w=2.44
-10.06%
|
155/45-18
d=23.49
w=2.75
-7.66%
|
155/50-18
d=24.10
w=3.05
-5.26%
|
155/55-18
d=24.71
w=3.36
-2.86%
|
155/60-18
d=25.32
w=3.66
-0.46%
|
155/65-18
d=25.93
w=3.97
+1.93%
|
155/70-18
d=26.54
w=4.27
+4.33%
|
155/75-18
d=27.15
w=4.58
+6.73%
|
155/80-18
d=27.76
w=4.88
+9.13%
|
155/85-18
d=28.37
w=5.19
+11.53%
|
| 165 |
165/25-18
d=21.25
w=1.62
-16.48%
|
165/30-18
d=21.90
w=1.95
-13.93%
|
165/35-18
d=22.55
w=2.27
-11.37%
|
165/40-18
d=23.20
w=2.60
-8.82%
|
165/45-18
d=23.85
w=2.92
-6.27%
|
165/50-18
d=24.50
w=3.25
-3.71%
|
165/55-18
d=25.15
w=3.57
-1.16%
|
165/60-18
d=25.80
w=3.90
+1.39%
|
165/65-18
d=26.44
w=4.22
+3.95%
|
165/70-18
d=27.09
w=4.55
+6.50%
|
165/75-18
d=27.74
w=4.87
+9.05%
|
165/80-18
d=28.39
w=5.20
+11.61%
|
165/85-18
d=29.04
w=5.52
+14.16%
|
| 175 |
175/25-18
d=21.44
w=1.72
-15.71%
|
175/30-18
d=22.13
w=2.07
-13.00%
|
175/35-18
d=22.82
w=2.41
-10.29%
|
175/40-18
d=23.51
w=2.76
-7.58%
|
175/45-18
d=24.20
w=3.10
-4.87%
|
175/50-18
d=24.89
w=3.44
-2.17%
|
175/55-18
d=25.58
w=3.79
+0.54%
|
175/60-18
d=26.27
w=4.13
+3.25%
|
175/65-18
d=26.96
w=4.48
+5.96%
|
175/70-18
d=27.65
w=4.82
+8.67%
|
175/75-18
d=28.33
w=5.17
+11.37%
|
175/80-18
d=29.02
w=5.51
+14.08%
|
175/85-18
d=29.71
w=5.86
+16.79%
|
| 185 |
185/25-18
d=21.64
w=1.82
-14.93%
|
185/30-18
d=22.37
w=2.19
-12.07%
|
185/35-18
d=23.10
w=2.55
-9.21%
|
185/40-18
d=23.83
w=2.91
-6.34%
|
185/45-18
d=24.56
w=3.28
-3.48%
|
185/50-18
d=25.28
w=3.64
-0.62%
|
185/55-18
d=26.01
w=4.01
+2.24%
|
185/60-18
d=26.74
w=4.37
+5.11%
|
185/65-18
d=27.47
w=4.73
+7.97%
|
185/70-18
d=28.20
w=5.10
+10.83%
|
185/75-18
d=28.93
w=5.46
+13.70%
|
185/80-18
d=29.65
w=5.83
+16.56%
|
185/85-18
d=30.38
w=6.19
+19.42%
|
| 195 |
195/25-18
d=21.84
w=1.92
-14.16%
|
195/30-18
d=22.61
w=2.30
-11.14%
|
195/35-18
d=23.37
w=2.69
-8.12%
|
195/40-18
d=24.14
w=3.07
-5.11%
|
195/45-18
d=24.91
w=3.45
-2.09%
|
195/50-18
d=25.68
w=3.84
+0.93%
|
195/55-18
d=26.44
w=4.22
+3.95%
|
195/60-18
d=27.21
w=4.61
+6.96%
|
195/65-18
d=27.98
w=4.99
+9.98%
|
195/70-18
d=28.75
w=5.37
+13.00%
|
195/75-18
d=29.52
w=5.76
+16.02%
|
195/80-18
d=30.28
w=6.14
+19.03%
|
195/85-18
d=31.05
w=6.53
+22.05%
|
| 205 |
205/25-18
d=22.04
w=2.02
-13.39%
|
205/30-18
d=22.84
w=2.42
-10.21%
|
205/35-18
d=23.65
w=2.82
-7.04%
|
205/40-18
d=24.46
w=3.23
-3.87%
|
205/45-18
d=25.26
w=3.63
-0.70%
|
205/50-18
d=26.07
w=4.04
+2.48%
|
205/55-18
d=26.88
w=4.44
+5.65%
|
205/60-18
d=27.69
w=4.84
+8.82%
|
205/65-18
d=28.49
w=5.25
+11.99%
|
205/70-18
d=29.30
w=5.65
+15.17%
|
205/75-18
d=30.11
w=6.05
+18.34%
|
205/80-18
d=30.91
w=6.46
+21.51%
|
205/85-18
d=31.72
w=6.86
+24.68%
|
| 215 |
215/25-18
d=22.23
w=2.12
-12.61%
|
215/30-18
d=23.08
w=2.54
-9.29%
|
215/35-18
d=23.93
w=2.96
-5.96%
|
215/40-18
d=24.77
w=3.39
-2.63%
|
215/45-18
d=25.62
w=3.81
+0.70%
|
215/50-18
d=26.46
w=4.23
+4.02%
|
215/55-18
d=27.31
w=4.66
+7.35%
|
215/60-18
d=28.16
w=5.08
+10.68%
|
215/65-18
d=29.00
w=5.50
+14.00%
|
215/70-18
d=29.85
w=5.93
+17.33%
|
215/75-18
d=30.70
w=6.35
+20.66%
|
215/80-18
d=31.54
w=6.77
+23.99%
|
215/85-18
d=32.39
w=7.19
+27.31%
|
| 225 |
225/25-18
d=22.43
w=2.21
-11.84%
|
225/30-18
d=23.31
w=2.66
-8.36%
|
225/35-18
d=24.20
w=3.10
-4.87%
|
225/40-18
d=25.09
w=3.54
-1.39%
|
225/45-18
d=25.97
w=3.99
+2.09%
|
225/50-18
d=26.86
w=4.43
+5.57%
|
225/55-18
d=27.74
w=4.87
+9.05%
|
225/60-18
d=28.63
w=5.31
+12.53%
|
225/65-18
d=29.52
w=5.76
+16.02%
|
225/70-18
d=30.40
w=6.20
+19.50%
|
225/75-18
d=31.29
w=6.64
+22.98%
|
225/80-18
d=32.17
w=7.09
+26.46%
|
225/85-18
d=33.06
w=7.53
+29.94%
|
| 235 |
235/25-18
d=22.63
w=2.31
-11.06%
|
235/30-18
d=23.55
w=2.78
-7.43%
|
235/35-18
d=24.48
w=3.24
-3.79%
|
235/40-18
d=25.40
w=3.70
-0.15%
|
235/45-18
d=26.33
w=4.16
+3.48%
|
235/50-18
d=27.25
w=4.63
+7.12%
|
235/55-18
d=28.18
w=5.09
+10.76%
|
235/60-18
d=29.10
w=5.55
+14.39%
|
235/65-18
d=30.03
w=6.01
+18.03%
|
235/70-18
d=30.95
w=6.48
+21.67%
|
235/75-18
d=31.88
w=6.94
+25.30%
|
235/80-18
d=32.80
w=7.40
+28.94%
|
235/85-18
d=33.73
w=7.86
+32.58%
|
| 245 |
245/25-18
d=22.82
w=2.41
-10.29%
|
245/30-18
d=23.79
w=2.89
-6.50%
|
245/35-18
d=24.75
w=3.38
-2.71%
|
245/40-18
d=25.72
w=3.86
+1.08%
|
245/45-18
d=26.68
w=4.34
+4.87%
|
245/50-18
d=27.65
w=4.82
+8.67%
|
245/55-18
d=28.61
w=5.31
+12.46%
|
245/60-18
d=29.57
w=5.79
+16.25%
|
245/65-18
d=30.54
w=6.27
+20.04%
|
245/70-18
d=31.50
w=6.75
+23.83%
|
245/75-18
d=32.47
w=7.23
+27.62%
|
245/80-18
d=33.43
w=7.72
+31.41%
|
245/85-18
d=34.40
w=8.20
+35.21%
|
| 255 |
255/25-18
d=23.02
w=2.51
-9.52%
|
255/30-18
d=24.02
w=3.01
-5.57%
|
255/35-18
d=25.03
w=3.51
-1.62%
|
255/40-18
d=26.03
w=4.02
+2.32%
|
255/45-18
d=27.04
w=4.52
+6.27%
|
255/50-18
d=28.04
w=5.02
+10.21%
|
255/55-18
d=29.04
w=5.52
+14.16%
|
255/60-18
d=30.05
w=6.02
+18.11%
|
255/65-18
d=31.05
w=6.53
+22.05%
|
255/70-18
d=32.06
w=7.03
+26.00%
|
255/75-18
d=33.06
w=7.53
+29.94%
|
255/80-18
d=34.06
w=8.03
+33.89%
|
255/85-18
d=35.07
w=8.53
+37.84%
|
| 265 |
265/25-18
d=23.22
w=2.61
-8.74%
|
265/30-18
d=24.26
w=3.13
-4.64%
|
265/35-18
d=25.30
w=3.65
-0.54%
|
265/40-18
d=26.35
w=4.17
+3.56%
|
265/45-18
d=27.39
w=4.69
+7.66%
|
265/50-18
d=28.43
w=5.22
+11.76%
|
265/55-18
d=29.48
w=5.74
+15.86%
|
265/60-18
d=30.52
w=6.26
+19.96%
|
265/65-18
d=31.56
w=6.78
+24.06%
|
265/70-18
d=32.61
w=7.30
+28.16%
|
265/75-18
d=33.65
w=7.82
+32.27%
|
265/80-18
d=34.69
w=8.35
+36.37%
|
265/85-18
d=35.74
w=8.87
+40.47%
|
| 275 |
275/25-18
d=23.41
w=2.71
-7.97%
|
275/30-18
d=24.50
w=3.25
-3.71%
|
275/35-18
d=25.58
w=3.79
+0.54%
|
275/40-18
d=26.66
w=4.33
+4.80%
|
275/45-18
d=27.74
w=4.87
+9.05%
|
275/50-18
d=28.83
w=5.41
+13.31%
|
275/55-18
d=29.91
w=5.95
+17.56%
|
275/60-18
d=30.99
w=6.50
+21.82%
|
275/65-18
d=32.07
w=7.04
+26.08%
|
275/70-18
d=33.16
w=7.58
+30.33%
|
275/75-18
d=34.24
w=8.12
+34.59%
|
275/80-18
d=35.32
w=8.66
+38.84%
|
275/85-18
d=36.41
w=9.20
+43.10%
|
| 285 |
285/25-18
d=23.61
w=2.81
-7.20%
|
285/30-18
d=24.73
w=3.37
-2.79%
|
285/35-18
d=25.85
w=3.93
+1.62%
|
285/40-18
d=26.98
w=4.49
+6.04%
|
285/45-18
d=28.10
w=5.05
+10.45%
|
285/50-18
d=29.22
w=5.61
+14.86%
|
285/55-18
d=30.34
w=6.17
+19.27%
|
285/60-18
d=31.46
w=6.73
+23.68%
|
285/65-18
d=32.59
w=7.29
+28.09%
|
285/70-18
d=33.71
w=7.85
+32.50%
|
285/75-18
d=34.83
w=8.42
+36.91%
|
285/80-18
d=35.95
w=8.98
+41.32%
|
285/85-18
d=37.07
w=9.54
+45.73%
|
| 295 |
295/25-18
d=23.81
w=2.90
-6.42%
|
295/30-18
d=24.97
w=3.48
-1.86%
|
295/35-18
d=26.13
w=4.06
+2.71%
|
295/40-18
d=27.29
w=4.65
+7.27%
|
295/45-18
d=28.45
w=5.23
+11.84%
|
295/50-18
d=29.61
w=5.81
+16.40%
|
295/55-18
d=30.78
w=6.39
+20.97%
|
295/60-18
d=31.94
w=6.97
+25.53%
|
295/65-18
d=33.10
w=7.55
+30.10%
|
295/70-18
d=34.26
w=8.13
+34.66%
|
295/75-18
d=35.42
w=8.71
+39.23%
|
295/80-18
d=36.58
w=9.29
+43.79%
|
295/85-18
d=37.74
w=9.87
+48.36%
|
| 305 |
305/25-18
d=24.00
w=3.00
-5.65%
|
305/30-18
d=25.20
w=3.60
-0.93%
|
305/35-18
d=26.41
w=4.20
+3.79%
|
305/40-18
d=27.61
w=4.80
+8.51%
|
305/45-18
d=28.81
w=5.40
+13.23%
|
305/50-18
d=30.01
w=6.00
+17.95%
|
305/55-18
d=31.21
w=6.60
+22.67%
|
305/60-18
d=32.41
w=7.20
+27.39%
|
305/65-18
d=33.61
w=7.81
+32.11%
|
305/70-18
d=34.81
w=8.41
+36.83%
|
305/75-18
d=36.01
w=9.01
+41.55%
|
305/80-18
d=37.21
w=9.61
+46.27%
|
305/85-18
d=38.41
w=10.21
+50.99%
|
| 315 |
315/25-18
d=24.20
w=3.10
-4.87%
|
315/30-18
d=25.44
w=3.72
0.00%
|
315/35-18
d=26.68
w=4.34
+4.87%
|
315/40-18
d=27.92
w=4.96
+9.75%
|
315/45-18
d=29.16
w=5.58
+14.62%
|
315/50-18
d=30.40
w=6.20
+19.50%
|
315/55-18
d=31.64
w=6.82
+24.37%
|
315/60-18
d=32.88
w=7.44
+29.25%
|
315/65-18
d=34.12
w=8.06
+34.12%
|
315/70-18
d=35.36
w=8.68
+39.00%
|
315/75-18
d=36.60
w=9.30
+43.87%
|
315/80-18
d=37.84
w=9.92
+48.75%
|
315/85-18
d=39.08
w=10.54
+53.62%
|
| 325 |
325/25-18
d=24.40
w=3.20
-4.10%
|
325/30-18
d=25.68
w=3.84
+0.93%
|
325/35-18
d=26.96
w=4.48
+5.96%
|
325/40-18
d=28.24
w=5.12
+10.99%
|
325/45-18
d=29.52
w=5.76
+16.02%
|
325/50-18
d=30.80
w=6.40
+21.05%
|
325/55-18
d=32.07
w=7.04
+26.08%
|
325/60-18
d=33.35
w=7.68
+31.10%
|
325/65-18
d=34.63
w=8.32
+36.13%
|
325/70-18
d=35.91
w=8.96
+41.16%
|
325/75-18
d=37.19
w=9.60
+46.19%
|
325/80-18
d=38.47
w=10.24
+51.22%
|
325/85-18
d=39.75
w=10.88
+56.25%
|
| 335 |
335/25-18
d=24.59
w=3.30
-3.33%
|
335/30-18
d=25.91
w=3.96
+1.86%
|
335/35-18
d=27.23
w=4.62
+7.04%
|
335/40-18
d=28.55
w=5.28
+12.23%
|
335/45-18
d=29.87
w=5.94
+17.41%
|
335/50-18
d=31.19
w=6.59
+22.59%
|
335/55-18
d=32.51
w=7.25
+27.78%
|
335/60-18
d=33.83
w=7.91
+32.96%
|
335/65-18
d=35.15
w=8.57
+38.15%
|
335/70-18
d=36.46
w=9.23
+43.33%
|
335/75-18
d=37.78
w=9.89
+48.51%
|
335/80-18
d=39.10
w=10.55
+53.70%
|
335/85-18
d=40.42
w=11.21
+58.88%
|
|
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!