| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 245/40-18 | 0.00 % | 50.00 | 1,000.00 | 25.72 | 3.86 | 98.00 |
| 325/30-18 | -0.15 % | 49.92 | 1,001.53 | 25.68 | 3.84 | 97.50 |
| 195/50-18 | -0.15 % | 49.92 | 1,001.53 | 25.68 | 3.84 | 97.50 |
| 165/60-18 | +0.31 % | 50.15 | 996.94 | 25.80 | 3.90 | 99.00 |
| 215/45-18 | -0.38 % | 49.81 | 1,003.83 | 25.62 | 3.81 | 96.75 |
| 275/35-18 | -0.54 % | 49.73 | 1,005.36 | 25.58 | 3.79 | 96.25 |
| 285/35-18 | +0.54 % | 50.27 | 994.64 | 25.85 | 3.93 | 99.75 |
| 175/55-18 | -0.54 % | 49.73 | 1,005.36 | 25.58 | 3.79 | 96.25 |
| 335/30-18 | +0.77 % | 50.38 | 992.35 | 25.91 | 3.96 | 100.50 |
| 155/65-18 | +0.84 % | 50.42 | 991.58 | 25.93 | 3.97 | 100.75 |
| 225/45-18 | +1.00 % | 50.50 | 990.05 | 25.97 | 3.99 | 101.25 |
| 315/30-18 | -1.07 % | 49.46 | 1,010.72 | 25.44 | 3.72 | 94.50 |
| 145/70-18 | +1.07 % | 50.54 | 989.28 | 25.99 | 4.00 | 101.50 |
| 185/55-18 | +1.15 % | 50.57 | 988.52 | 26.01 | 4.01 | 101.75 |
| 145/65-18 | -1.15 % | 49.43 | 1,011.48 | 25.42 | 3.71 | 94.25 |
| 235/40-18 | -1.22 % | 49.39 | 1,012.25 | 25.40 | 3.70 | 94.00 |
| 255/40-18 | +1.22 % | 50.61 | 987.75 | 26.03 | 4.02 | 102.00 |
| 205/50-18 | +1.38 % | 50.69 | 986.22 | 26.07 | 4.04 | 102.50 |
| 155/60-18 | -1.53 % | 49.23 | 1,015.31 | 25.32 | 3.66 | 93.00 |
| 265/35-18 | -1.61 % | 49.20 | 1,016.07 | 25.30 | 3.65 | 92.75 |
| 295/35-18 | +1.61 % | 50.80 | 983.93 | 26.13 | 4.06 | 103.25 |
| 185/50-18 | -1.68 % | 49.16 | 1,016.84 | 25.28 | 3.64 | 92.50 |
| 205/45-18 | -1.76 % | 49.12 | 1,017.61 | 25.26 | 3.63 | 92.25 |
| 305/30-18 | -1.99 % | 49.00 | 1,019.90 | 25.20 | 3.60 | 91.50 |
| 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
-18.91%
|
145/30-18
d=21.43
w=1.71
-16.69%
|
145/35-18
d=22.00
w=2.00
-14.47%
|
145/40-18
d=22.57
w=2.28
-12.25%
|
145/45-18
d=23.14
w=2.57
-10.03%
|
145/50-18
d=23.71
w=2.85
-7.81%
|
145/55-18
d=24.28
w=3.14
-5.59%
|
145/60-18
d=24.85
w=3.43
-3.37%
|
145/65-18
d=25.42
w=3.71
-1.15%
|
145/70-18
d=25.99
w=4.00
+1.07%
|
145/75-18
d=26.56
w=4.28
+3.29%
|
145/80-18
d=27.13
w=4.57
+5.51%
|
145/85-18
d=27.70
w=4.85
+7.73%
|
| 155 |
155/25-18
d=21.05
w=1.53
-18.14%
|
155/30-18
d=21.66
w=1.83
-15.77%
|
155/35-18
d=22.27
w=2.14
-13.40%
|
155/40-18
d=22.88
w=2.44
-11.02%
|
155/45-18
d=23.49
w=2.75
-8.65%
|
155/50-18
d=24.10
w=3.05
-6.28%
|
155/55-18
d=24.71
w=3.36
-3.90%
|
155/60-18
d=25.32
w=3.66
-1.53%
|
155/65-18
d=25.93
w=3.97
+0.84%
|
155/70-18
d=26.54
w=4.27
+3.21%
|
155/75-18
d=27.15
w=4.58
+5.59%
|
155/80-18
d=27.76
w=4.88
+7.96%
|
155/85-18
d=28.37
w=5.19
+10.33%
|
| 165 |
165/25-18
d=21.25
w=1.62
-17.38%
|
165/30-18
d=21.90
w=1.95
-14.85%
|
165/35-18
d=22.55
w=2.27
-12.32%
|
165/40-18
d=23.20
w=2.60
-9.80%
|
165/45-18
d=23.85
w=2.92
-7.27%
|
165/50-18
d=24.50
w=3.25
-4.75%
|
165/55-18
d=25.15
w=3.57
-2.22%
|
165/60-18
d=25.80
w=3.90
+0.31%
|
165/65-18
d=26.44
w=4.22
+2.83%
|
165/70-18
d=27.09
w=4.55
+5.36%
|
165/75-18
d=27.74
w=4.87
+7.88%
|
165/80-18
d=28.39
w=5.20
+10.41%
|
165/85-18
d=29.04
w=5.52
+12.94%
|
| 175 |
175/25-18
d=21.44
w=1.72
-16.61%
|
175/30-18
d=22.13
w=2.07
-13.93%
|
175/35-18
d=22.82
w=2.41
-11.25%
|
175/40-18
d=23.51
w=2.76
-8.57%
|
175/45-18
d=24.20
w=3.10
-5.89%
|
175/50-18
d=24.89
w=3.44
-3.21%
|
175/55-18
d=25.58
w=3.79
-0.54%
|
175/60-18
d=26.27
w=4.13
+2.14%
|
175/65-18
d=26.96
w=4.48
+4.82%
|
175/70-18
d=27.65
w=4.82
+7.50%
|
175/75-18
d=28.33
w=5.17
+10.18%
|
175/80-18
d=29.02
w=5.51
+12.86%
|
175/85-18
d=29.71
w=5.86
+15.54%
|
| 185 |
185/25-18
d=21.64
w=1.82
-15.85%
|
185/30-18
d=22.37
w=2.19
-13.01%
|
185/35-18
d=23.10
w=2.55
-10.18%
|
185/40-18
d=23.83
w=2.91
-7.35%
|
185/45-18
d=24.56
w=3.28
-4.52%
|
185/50-18
d=25.28
w=3.64
-1.68%
|
185/55-18
d=26.01
w=4.01
+1.15%
|
185/60-18
d=26.74
w=4.37
+3.98%
|
185/65-18
d=27.47
w=4.73
+6.81%
|
185/70-18
d=28.20
w=5.10
+9.64%
|
185/75-18
d=28.93
w=5.46
+12.48%
|
185/80-18
d=29.65
w=5.83
+15.31%
|
185/85-18
d=30.38
w=6.19
+18.14%
|
| 195 |
195/25-18
d=21.84
w=1.92
-15.08%
|
195/30-18
d=22.61
w=2.30
-12.09%
|
195/35-18
d=23.37
w=2.69
-9.11%
|
195/40-18
d=24.14
w=3.07
-6.12%
|
195/45-18
d=24.91
w=3.45
-3.14%
|
195/50-18
d=25.68
w=3.84
-0.15%
|
195/55-18
d=26.44
w=4.22
+2.83%
|
195/60-18
d=27.21
w=4.61
+5.82%
|
195/65-18
d=27.98
w=4.99
+8.80%
|
195/70-18
d=28.75
w=5.37
+11.79%
|
195/75-18
d=29.52
w=5.76
+14.77%
|
195/80-18
d=30.28
w=6.14
+17.76%
|
195/85-18
d=31.05
w=6.53
+20.74%
|
| 205 |
205/25-18
d=22.04
w=2.02
-14.31%
|
205/30-18
d=22.84
w=2.42
-11.18%
|
205/35-18
d=23.65
w=2.82
-8.04%
|
205/40-18
d=24.46
w=3.23
-4.90%
|
205/45-18
d=25.26
w=3.63
-1.76%
|
205/50-18
d=26.07
w=4.04
+1.38%
|
205/55-18
d=26.88
w=4.44
+4.52%
|
205/60-18
d=27.69
w=4.84
+7.65%
|
205/65-18
d=28.49
w=5.25
+10.79%
|
205/70-18
d=29.30
w=5.65
+13.93%
|
205/75-18
d=30.11
w=6.05
+17.07%
|
205/80-18
d=30.91
w=6.46
+20.21%
|
205/85-18
d=31.72
w=6.86
+23.35%
|
| 215 |
215/25-18
d=22.23
w=2.12
-13.55%
|
215/30-18
d=23.08
w=2.54
-10.26%
|
215/35-18
d=23.93
w=2.96
-6.97%
|
215/40-18
d=24.77
w=3.39
-3.67%
|
215/45-18
d=25.62
w=3.81
-0.38%
|
215/50-18
d=26.46
w=4.23
+2.91%
|
215/55-18
d=27.31
w=4.66
+6.20%
|
215/60-18
d=28.16
w=5.08
+9.49%
|
215/65-18
d=29.00
w=5.50
+12.78%
|
215/70-18
d=29.85
w=5.93
+16.07%
|
215/75-18
d=30.70
w=6.35
+19.37%
|
215/80-18
d=31.54
w=6.77
+22.66%
|
215/85-18
d=32.39
w=7.19
+25.95%
|
| 225 |
225/25-18
d=22.43
w=2.21
-12.78%
|
225/30-18
d=23.31
w=2.66
-9.34%
|
225/35-18
d=24.20
w=3.10
-5.89%
|
225/40-18
d=25.09
w=3.54
-2.45%
|
225/45-18
d=25.97
w=3.99
+1.00%
|
225/50-18
d=26.86
w=4.43
+4.44%
|
225/55-18
d=27.74
w=4.87
+7.88%
|
225/60-18
d=28.63
w=5.31
+11.33%
|
225/65-18
d=29.52
w=5.76
+14.77%
|
225/70-18
d=30.40
w=6.20
+18.22%
|
225/75-18
d=31.29
w=6.64
+21.66%
|
225/80-18
d=32.17
w=7.09
+25.11%
|
225/85-18
d=33.06
w=7.53
+28.55%
|
| 235 |
235/25-18
d=22.63
w=2.31
-12.02%
|
235/30-18
d=23.55
w=2.78
-8.42%
|
235/35-18
d=24.48
w=3.24
-4.82%
|
235/40-18
d=25.40
w=3.70
-1.22%
|
235/45-18
d=26.33
w=4.16
+2.37%
|
235/50-18
d=27.25
w=4.63
+5.97%
|
235/55-18
d=28.18
w=5.09
+9.57%
|
235/60-18
d=29.10
w=5.55
+13.17%
|
235/65-18
d=30.03
w=6.01
+16.76%
|
235/70-18
d=30.95
w=6.48
+20.36%
|
235/75-18
d=31.88
w=6.94
+23.96%
|
235/80-18
d=32.80
w=7.40
+27.56%
|
235/85-18
d=33.73
w=7.86
+31.15%
|
| 245 |
245/25-18
d=22.82
w=2.41
-11.25%
|
245/30-18
d=23.79
w=2.89
-7.50%
|
245/35-18
d=24.75
w=3.38
-3.75%
|
245/40-18
d=25.72
w=3.86
0.00%
|
245/45-18
d=26.68
w=4.34
+3.75%
|
245/50-18
d=27.65
w=4.82
+7.50%
|
245/55-18
d=28.61
w=5.31
+11.25%
|
245/60-18
d=29.57
w=5.79
+15.00%
|
245/65-18
d=30.54
w=6.27
+18.75%
|
245/70-18
d=31.50
w=6.75
+22.50%
|
245/75-18
d=32.47
w=7.23
+26.26%
|
245/80-18
d=33.43
w=7.72
+30.01%
|
245/85-18
d=34.40
w=8.20
+33.76%
|
| 255 |
255/25-18
d=23.02
w=2.51
-10.49%
|
255/30-18
d=24.02
w=3.01
-6.58%
|
255/35-18
d=25.03
w=3.51
-2.68%
|
255/40-18
d=26.03
w=4.02
+1.22%
|
255/45-18
d=27.04
w=4.52
+5.13%
|
255/50-18
d=28.04
w=5.02
+9.03%
|
255/55-18
d=29.04
w=5.52
+12.94%
|
255/60-18
d=30.05
w=6.02
+16.84%
|
255/65-18
d=31.05
w=6.53
+20.74%
|
255/70-18
d=32.06
w=7.03
+24.65%
|
255/75-18
d=33.06
w=7.53
+28.55%
|
255/80-18
d=34.06
w=8.03
+32.46%
|
255/85-18
d=35.07
w=8.53
+36.36%
|
| 265 |
265/25-18
d=23.22
w=2.61
-9.72%
|
265/30-18
d=24.26
w=3.13
-5.66%
|
265/35-18
d=25.30
w=3.65
-1.61%
|
265/40-18
d=26.35
w=4.17
+2.45%
|
265/45-18
d=27.39
w=4.69
+6.51%
|
265/50-18
d=28.43
w=5.22
+10.56%
|
265/55-18
d=29.48
w=5.74
+14.62%
|
265/60-18
d=30.52
w=6.26
+18.68%
|
265/65-18
d=31.56
w=6.78
+22.73%
|
265/70-18
d=32.61
w=7.30
+26.79%
|
265/75-18
d=33.65
w=7.82
+30.85%
|
265/80-18
d=34.69
w=8.35
+34.91%
|
265/85-18
d=35.74
w=8.87
+38.96%
|
| 275 |
275/25-18
d=23.41
w=2.71
-8.96%
|
275/30-18
d=24.50
w=3.25
-4.75%
|
275/35-18
d=25.58
w=3.79
-0.54%
|
275/40-18
d=26.66
w=4.33
+3.67%
|
275/45-18
d=27.74
w=4.87
+7.88%
|
275/50-18
d=28.83
w=5.41
+12.09%
|
275/55-18
d=29.91
w=5.95
+16.30%
|
275/60-18
d=30.99
w=6.50
+20.51%
|
275/65-18
d=32.07
w=7.04
+24.72%
|
275/70-18
d=33.16
w=7.58
+28.93%
|
275/75-18
d=34.24
w=8.12
+33.14%
|
275/80-18
d=35.32
w=8.66
+37.35%
|
275/85-18
d=36.41
w=9.20
+41.56%
|
| 285 |
285/25-18
d=23.61
w=2.81
-8.19%
|
285/30-18
d=24.73
w=3.37
-3.83%
|
285/35-18
d=25.85
w=3.93
+0.54%
|
285/40-18
d=26.98
w=4.49
+4.90%
|
285/45-18
d=28.10
w=5.05
+9.26%
|
285/50-18
d=29.22
w=5.61
+13.63%
|
285/55-18
d=30.34
w=6.17
+17.99%
|
285/60-18
d=31.46
w=6.73
+22.35%
|
285/65-18
d=32.59
w=7.29
+26.71%
|
285/70-18
d=33.71
w=7.85
+31.08%
|
285/75-18
d=34.83
w=8.42
+35.44%
|
285/80-18
d=35.95
w=8.98
+39.80%
|
285/85-18
d=37.07
w=9.54
+44.17%
|
| 295 |
295/25-18
d=23.81
w=2.90
-7.42%
|
295/30-18
d=24.97
w=3.48
-2.91%
|
295/35-18
d=26.13
w=4.06
+1.61%
|
295/40-18
d=27.29
w=4.65
+6.12%
|
295/45-18
d=28.45
w=5.23
+10.64%
|
295/50-18
d=29.61
w=5.81
+15.16%
|
295/55-18
d=30.78
w=6.39
+19.67%
|
295/60-18
d=31.94
w=6.97
+24.19%
|
295/65-18
d=33.10
w=7.55
+28.70%
|
295/70-18
d=34.26
w=8.13
+33.22%
|
295/75-18
d=35.42
w=8.71
+37.74%
|
295/80-18
d=36.58
w=9.29
+42.25%
|
295/85-18
d=37.74
w=9.87
+46.77%
|
| 305 |
305/25-18
d=24.00
w=3.00
-6.66%
|
305/30-18
d=25.20
w=3.60
-1.99%
|
305/35-18
d=26.41
w=4.20
+2.68%
|
305/40-18
d=27.61
w=4.80
+7.35%
|
305/45-18
d=28.81
w=5.40
+12.02%
|
305/50-18
d=30.01
w=6.00
+16.69%
|
305/55-18
d=31.21
w=6.60
+21.36%
|
305/60-18
d=32.41
w=7.20
+26.03%
|
305/65-18
d=33.61
w=7.81
+30.70%
|
305/70-18
d=34.81
w=8.41
+35.36%
|
305/75-18
d=36.01
w=9.01
+40.03%
|
305/80-18
d=37.21
w=9.61
+44.70%
|
305/85-18
d=38.41
w=10.21
+49.37%
|
| 315 |
315/25-18
d=24.20
w=3.10
-5.89%
|
315/30-18
d=25.44
w=3.72
-1.07%
|
315/35-18
d=26.68
w=4.34
+3.75%
|
315/40-18
d=27.92
w=4.96
+8.57%
|
315/45-18
d=29.16
w=5.58
+13.40%
|
315/50-18
d=30.40
w=6.20
+18.22%
|
315/55-18
d=31.64
w=6.82
+23.04%
|
315/60-18
d=32.88
w=7.44
+27.86%
|
315/65-18
d=34.12
w=8.06
+32.69%
|
315/70-18
d=35.36
w=8.68
+37.51%
|
315/75-18
d=36.60
w=9.30
+42.33%
|
315/80-18
d=37.84
w=9.92
+47.15%
|
315/85-18
d=39.08
w=10.54
+51.97%
|
| 325 |
325/25-18
d=24.40
w=3.20
-5.13%
|
325/30-18
d=25.68
w=3.84
-0.15%
|
325/35-18
d=26.96
w=4.48
+4.82%
|
325/40-18
d=28.24
w=5.12
+9.80%
|
325/45-18
d=29.52
w=5.76
+14.77%
|
325/50-18
d=30.80
w=6.40
+19.75%
|
325/55-18
d=32.07
w=7.04
+24.72%
|
325/60-18
d=33.35
w=7.68
+29.70%
|
325/65-18
d=34.63
w=8.32
+34.68%
|
325/70-18
d=35.91
w=8.96
+39.65%
|
325/75-18
d=37.19
w=9.60
+44.63%
|
325/80-18
d=38.47
w=10.24
+49.60%
|
325/85-18
d=39.75
w=10.88
+54.58%
|
| 335 |
335/25-18
d=24.59
w=3.30
-4.36%
|
335/30-18
d=25.91
w=3.96
+0.77%
|
335/35-18
d=27.23
w=4.62
+5.89%
|
335/40-18
d=28.55
w=5.28
+11.02%
|
335/45-18
d=29.87
w=5.94
+16.15%
|
335/50-18
d=31.19
w=6.59
+21.28%
|
335/55-18
d=32.51
w=7.25
+26.41%
|
335/60-18
d=33.83
w=7.91
+31.54%
|
335/65-18
d=35.15
w=8.57
+36.67%
|
335/70-18
d=36.46
w=9.23
+41.79%
|
335/75-18
d=37.78
w=9.89
+46.92%
|
335/80-18
d=39.10
w=10.55
+52.05%
|
335/85-18
d=40.42
w=11.21
+57.18%
|
|
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!