| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 315/25-18 | 0.00 % | 50.00 | 1,000.00 | 24.20 | 3.10 | 78.75 |
| 225/35-18 | 0.00 % | 50.00 | 1,000.00 | 24.20 | 3.10 | 78.75 |
| 175/45-18 | 0.00 % | 50.00 | 1,000.00 | 24.20 | 3.10 | 78.75 |
| 265/30-18 | +0.24 % | 50.12 | 997.56 | 24.26 | 3.13 | 79.50 |
| 195/40-18 | -0.24 % | 49.88 | 1,002.44 | 24.14 | 3.07 | 78.00 |
| 145/55-18 | +0.33 % | 50.16 | 996.75 | 24.28 | 3.14 | 79.75 |
| 155/50-18 | -0.41 % | 49.80 | 1,004.07 | 24.10 | 3.05 | 77.50 |
| 255/30-18 | -0.73 % | 49.63 | 1,007.32 | 24.02 | 3.01 | 76.50 |
| 305/25-18 | -0.81 % | 49.59 | 1,008.13 | 24.00 | 3.00 | 76.25 |
| 325/25-18 | +0.81 % | 50.41 | 991.87 | 24.40 | 3.20 | 81.25 |
| 205/40-18 | +1.06 % | 50.53 | 989.43 | 24.46 | 3.23 | 82.00 |
| 235/35-18 | +1.14 % | 50.57 | 988.61 | 24.48 | 3.24 | 82.25 |
| 215/35-18 | -1.14 % | 49.43 | 1,011.39 | 23.93 | 2.96 | 75.25 |
| 275/30-18 | +1.22 % | 50.61 | 987.80 | 24.50 | 3.25 | 82.50 |
| 165/50-18 | +1.22 % | 50.61 | 987.80 | 24.50 | 3.25 | 82.50 |
| 165/45-18 | -1.46 % | 49.27 | 1,014.64 | 23.85 | 2.92 | 74.25 |
| 185/45-18 | +1.46 % | 50.73 | 985.36 | 24.56 | 3.28 | 83.25 |
| 185/40-18 | -1.55 % | 49.23 | 1,015.45 | 23.83 | 2.91 | 74.00 |
| 295/25-18 | -1.63 % | 49.19 | 1,016.27 | 23.81 | 2.90 | 73.75 |
| 335/25-18 | +1.63 % | 50.81 | 983.73 | 24.59 | 3.30 | 83.75 |
| 245/30-18 | -1.71 % | 49.15 | 1,017.08 | 23.79 | 2.89 | 73.50 |
| 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
-13.83%
|
145/30-18
d=21.43
w=1.71
-11.47%
|
145/35-18
d=22.00
w=2.00
-9.11%
|
145/40-18
d=22.57
w=2.28
-6.75%
|
145/45-18
d=23.14
w=2.57
-4.39%
|
145/50-18
d=23.71
w=2.85
-2.03%
|
145/55-18
d=24.28
w=3.14
+0.33%
|
145/60-18
d=24.85
w=3.43
+2.68%
|
145/65-18
d=25.42
w=3.71
+5.04%
|
145/70-18
d=25.99
w=4.00
+7.40%
|
145/75-18
d=26.56
w=4.28
+9.76%
|
145/80-18
d=27.13
w=4.57
+12.12%
|
145/85-18
d=27.70
w=4.85
+14.48%
|
| 155 |
155/25-18
d=21.05
w=1.53
-13.01%
|
155/30-18
d=21.66
w=1.83
-10.49%
|
155/35-18
d=22.27
w=2.14
-7.97%
|
155/40-18
d=22.88
w=2.44
-5.45%
|
155/45-18
d=23.49
w=2.75
-2.93%
|
155/50-18
d=24.10
w=3.05
-0.41%
|
155/55-18
d=24.71
w=3.36
+2.11%
|
155/60-18
d=25.32
w=3.66
+4.64%
|
155/65-18
d=25.93
w=3.97
+7.16%
|
155/70-18
d=26.54
w=4.27
+9.68%
|
155/75-18
d=27.15
w=4.58
+12.20%
|
155/80-18
d=27.76
w=4.88
+14.72%
|
155/85-18
d=28.37
w=5.19
+17.24%
|
| 165 |
165/25-18
d=21.25
w=1.62
-12.20%
|
165/30-18
d=21.90
w=1.95
-9.52%
|
165/35-18
d=22.55
w=2.27
-6.83%
|
165/40-18
d=23.20
w=2.60
-4.15%
|
165/45-18
d=23.85
w=2.92
-1.46%
|
165/50-18
d=24.50
w=3.25
+1.22%
|
165/55-18
d=25.15
w=3.57
+3.90%
|
165/60-18
d=25.80
w=3.90
+6.59%
|
165/65-18
d=26.44
w=4.22
+9.27%
|
165/70-18
d=27.09
w=4.55
+11.96%
|
165/75-18
d=27.74
w=4.87
+14.64%
|
165/80-18
d=28.39
w=5.20
+17.33%
|
165/85-18
d=29.04
w=5.52
+20.01%
|
| 175 |
175/25-18
d=21.44
w=1.72
-11.39%
|
175/30-18
d=22.13
w=2.07
-8.54%
|
175/35-18
d=22.82
w=2.41
-5.69%
|
175/40-18
d=23.51
w=2.76
-2.85%
|
175/45-18
d=24.20
w=3.10
0.00%
|
175/50-18
d=24.89
w=3.44
+2.85%
|
175/55-18
d=25.58
w=3.79
+5.69%
|
175/60-18
d=26.27
w=4.13
+8.54%
|
175/65-18
d=26.96
w=4.48
+11.39%
|
175/70-18
d=27.65
w=4.82
+14.23%
|
175/75-18
d=28.33
w=5.17
+17.08%
|
175/80-18
d=29.02
w=5.51
+19.93%
|
175/85-18
d=29.71
w=5.86
+22.78%
|
| 185 |
185/25-18
d=21.64
w=1.82
-10.57%
|
185/30-18
d=22.37
w=2.19
-7.56%
|
185/35-18
d=23.10
w=2.55
-4.56%
|
185/40-18
d=23.83
w=2.91
-1.55%
|
185/45-18
d=24.56
w=3.28
+1.46%
|
185/50-18
d=25.28
w=3.64
+4.47%
|
185/55-18
d=26.01
w=4.01
+7.48%
|
185/60-18
d=26.74
w=4.37
+10.49%
|
185/65-18
d=27.47
w=4.73
+13.50%
|
185/70-18
d=28.20
w=5.10
+16.51%
|
185/75-18
d=28.93
w=5.46
+19.52%
|
185/80-18
d=29.65
w=5.83
+22.53%
|
185/85-18
d=30.38
w=6.19
+25.54%
|
| 195 |
195/25-18
d=21.84
w=1.92
-9.76%
|
195/30-18
d=22.61
w=2.30
-6.59%
|
195/35-18
d=23.37
w=2.69
-3.42%
|
195/40-18
d=24.14
w=3.07
-0.24%
|
195/45-18
d=24.91
w=3.45
+2.93%
|
195/50-18
d=25.68
w=3.84
+6.10%
|
195/55-18
d=26.44
w=4.22
+9.27%
|
195/60-18
d=27.21
w=4.61
+12.45%
|
195/65-18
d=27.98
w=4.99
+15.62%
|
195/70-18
d=28.75
w=5.37
+18.79%
|
195/75-18
d=29.52
w=5.76
+21.96%
|
195/80-18
d=30.28
w=6.14
+25.13%
|
195/85-18
d=31.05
w=6.53
+28.31%
|
| 205 |
205/25-18
d=22.04
w=2.02
-8.95%
|
205/30-18
d=22.84
w=2.42
-5.61%
|
205/35-18
d=23.65
w=2.82
-2.28%
|
205/40-18
d=24.46
w=3.23
+1.06%
|
205/45-18
d=25.26
w=3.63
+4.39%
|
205/50-18
d=26.07
w=4.04
+7.73%
|
205/55-18
d=26.88
w=4.44
+11.06%
|
205/60-18
d=27.69
w=4.84
+14.40%
|
205/65-18
d=28.49
w=5.25
+17.73%
|
205/70-18
d=29.30
w=5.65
+21.07%
|
205/75-18
d=30.11
w=6.05
+24.40%
|
205/80-18
d=30.91
w=6.46
+27.74%
|
205/85-18
d=31.72
w=6.86
+31.07%
|
| 215 |
215/25-18
d=22.23
w=2.12
-8.13%
|
215/30-18
d=23.08
w=2.54
-4.64%
|
215/35-18
d=23.93
w=2.96
-1.14%
|
215/40-18
d=24.77
w=3.39
+2.36%
|
215/45-18
d=25.62
w=3.81
+5.86%
|
215/50-18
d=26.46
w=4.23
+9.35%
|
215/55-18
d=27.31
w=4.66
+12.85%
|
215/60-18
d=28.16
w=5.08
+16.35%
|
215/65-18
d=29.00
w=5.50
+19.85%
|
215/70-18
d=29.85
w=5.93
+23.34%
|
215/75-18
d=30.70
w=6.35
+26.84%
|
215/80-18
d=31.54
w=6.77
+30.34%
|
215/85-18
d=32.39
w=7.19
+33.84%
|
| 225 |
225/25-18
d=22.43
w=2.21
-7.32%
|
225/30-18
d=23.31
w=2.66
-3.66%
|
225/35-18
d=24.20
w=3.10
0.00%
|
225/40-18
d=25.09
w=3.54
+3.66%
|
225/45-18
d=25.97
w=3.99
+7.32%
|
225/50-18
d=26.86
w=4.43
+10.98%
|
225/55-18
d=27.74
w=4.87
+14.64%
|
225/60-18
d=28.63
w=5.31
+18.30%
|
225/65-18
d=29.52
w=5.76
+21.96%
|
225/70-18
d=30.40
w=6.20
+25.62%
|
225/75-18
d=31.29
w=6.64
+29.28%
|
225/80-18
d=32.17
w=7.09
+32.94%
|
225/85-18
d=33.06
w=7.53
+36.60%
|
| 235 |
235/25-18
d=22.63
w=2.31
-6.51%
|
235/30-18
d=23.55
w=2.78
-2.68%
|
235/35-18
d=24.48
w=3.24
+1.14%
|
235/40-18
d=25.40
w=3.70
+4.96%
|
235/45-18
d=26.33
w=4.16
+8.78%
|
235/50-18
d=27.25
w=4.63
+12.61%
|
235/55-18
d=28.18
w=5.09
+16.43%
|
235/60-18
d=29.10
w=5.55
+20.25%
|
235/65-18
d=30.03
w=6.01
+24.08%
|
235/70-18
d=30.95
w=6.48
+27.90%
|
235/75-18
d=31.88
w=6.94
+31.72%
|
235/80-18
d=32.80
w=7.40
+35.55%
|
235/85-18
d=33.73
w=7.86
+39.37%
|
| 245 |
245/25-18
d=22.82
w=2.41
-5.69%
|
245/30-18
d=23.79
w=2.89
-1.71%
|
245/35-18
d=24.75
w=3.38
+2.28%
|
245/40-18
d=25.72
w=3.86
+6.26%
|
245/45-18
d=26.68
w=4.34
+10.25%
|
245/50-18
d=27.65
w=4.82
+14.23%
|
245/55-18
d=28.61
w=5.31
+18.22%
|
245/60-18
d=29.57
w=5.79
+22.21%
|
245/65-18
d=30.54
w=6.27
+26.19%
|
245/70-18
d=31.50
w=6.75
+30.18%
|
245/75-18
d=32.47
w=7.23
+34.16%
|
245/80-18
d=33.43
w=7.72
+38.15%
|
245/85-18
d=34.40
w=8.20
+42.13%
|
| 255 |
255/25-18
d=23.02
w=2.51
-4.88%
|
255/30-18
d=24.02
w=3.01
-0.73%
|
255/35-18
d=25.03
w=3.51
+3.42%
|
255/40-18
d=26.03
w=4.02
+7.56%
|
255/45-18
d=27.04
w=4.52
+11.71%
|
255/50-18
d=28.04
w=5.02
+15.86%
|
255/55-18
d=29.04
w=5.52
+20.01%
|
255/60-18
d=30.05
w=6.02
+24.16%
|
255/65-18
d=31.05
w=6.53
+28.31%
|
255/70-18
d=32.06
w=7.03
+32.45%
|
255/75-18
d=33.06
w=7.53
+36.60%
|
255/80-18
d=34.06
w=8.03
+40.75%
|
255/85-18
d=35.07
w=8.53
+44.90%
|
| 265 |
265/25-18
d=23.22
w=2.61
-4.07%
|
265/30-18
d=24.26
w=3.13
+0.24%
|
265/35-18
d=25.30
w=3.65
+4.56%
|
265/40-18
d=26.35
w=4.17
+8.87%
|
265/45-18
d=27.39
w=4.69
+13.18%
|
265/50-18
d=28.43
w=5.22
+17.49%
|
265/55-18
d=29.48
w=5.74
+21.80%
|
265/60-18
d=30.52
w=6.26
+26.11%
|
265/65-18
d=31.56
w=6.78
+30.42%
|
265/70-18
d=32.61
w=7.30
+34.73%
|
265/75-18
d=33.65
w=7.82
+39.04%
|
265/80-18
d=34.69
w=8.35
+43.35%
|
265/85-18
d=35.74
w=8.87
+47.67%
|
| 275 |
275/25-18
d=23.41
w=2.71
-3.25%
|
275/30-18
d=24.50
w=3.25
+1.22%
|
275/35-18
d=25.58
w=3.79
+5.69%
|
275/40-18
d=26.66
w=4.33
+10.17%
|
275/45-18
d=27.74
w=4.87
+14.64%
|
275/50-18
d=28.83
w=5.41
+19.12%
|
275/55-18
d=29.91
w=5.95
+23.59%
|
275/60-18
d=30.99
w=6.50
+28.06%
|
275/65-18
d=32.07
w=7.04
+32.54%
|
275/70-18
d=33.16
w=7.58
+37.01%
|
275/75-18
d=34.24
w=8.12
+41.48%
|
275/80-18
d=35.32
w=8.66
+45.96%
|
275/85-18
d=36.41
w=9.20
+50.43%
|
| 285 |
285/25-18
d=23.61
w=2.81
-2.44%
|
285/30-18
d=24.73
w=3.37
+2.20%
|
285/35-18
d=25.85
w=3.93
+6.83%
|
285/40-18
d=26.98
w=4.49
+11.47%
|
285/45-18
d=28.10
w=5.05
+16.11%
|
285/50-18
d=29.22
w=5.61
+20.74%
|
285/55-18
d=30.34
w=6.17
+25.38%
|
285/60-18
d=31.46
w=6.73
+30.01%
|
285/65-18
d=32.59
w=7.29
+34.65%
|
285/70-18
d=33.71
w=7.85
+39.29%
|
285/75-18
d=34.83
w=8.42
+43.92%
|
285/80-18
d=35.95
w=8.98
+48.56%
|
285/85-18
d=37.07
w=9.54
+53.20%
|
| 295 |
295/25-18
d=23.81
w=2.90
-1.63%
|
295/30-18
d=24.97
w=3.48
+3.17%
|
295/35-18
d=26.13
w=4.06
+7.97%
|
295/40-18
d=27.29
w=4.65
+12.77%
|
295/45-18
d=28.45
w=5.23
+17.57%
|
295/50-18
d=29.61
w=5.81
+22.37%
|
295/55-18
d=30.78
w=6.39
+27.17%
|
295/60-18
d=31.94
w=6.97
+31.97%
|
295/65-18
d=33.10
w=7.55
+36.77%
|
295/70-18
d=34.26
w=8.13
+41.56%
|
295/75-18
d=35.42
w=8.71
+46.36%
|
295/80-18
d=36.58
w=9.29
+51.16%
|
295/85-18
d=37.74
w=9.87
+55.96%
|
| 305 |
305/25-18
d=24.00
w=3.00
-0.81%
|
305/30-18
d=25.20
w=3.60
+4.15%
|
305/35-18
d=26.41
w=4.20
+9.11%
|
305/40-18
d=27.61
w=4.80
+14.07%
|
305/45-18
d=28.81
w=5.40
+19.03%
|
305/50-18
d=30.01
w=6.00
+24.00%
|
305/55-18
d=31.21
w=6.60
+28.96%
|
305/60-18
d=32.41
w=7.20
+33.92%
|
305/65-18
d=33.61
w=7.81
+38.88%
|
305/70-18
d=34.81
w=8.41
+43.84%
|
305/75-18
d=36.01
w=9.01
+48.80%
|
305/80-18
d=37.21
w=9.61
+53.77%
|
305/85-18
d=38.41
w=10.21
+58.73%
|
| 315 |
315/25-18
d=24.20
w=3.10
0.00%
|
315/30-18
d=25.44
w=3.72
+5.12%
|
315/35-18
d=26.68
w=4.34
+10.25%
|
315/40-18
d=27.92
w=4.96
+15.37%
|
315/45-18
d=29.16
w=5.58
+20.50%
|
315/50-18
d=30.40
w=6.20
+25.62%
|
315/55-18
d=31.64
w=6.82
+30.75%
|
315/60-18
d=32.88
w=7.44
+35.87%
|
315/65-18
d=34.12
w=8.06
+41.00%
|
315/70-18
d=35.36
w=8.68
+46.12%
|
315/75-18
d=36.60
w=9.30
+51.24%
|
315/80-18
d=37.84
w=9.92
+56.37%
|
315/85-18
d=39.08
w=10.54
+61.49%
|
| 325 |
325/25-18
d=24.40
w=3.20
+0.81%
|
325/30-18
d=25.68
w=3.84
+6.10%
|
325/35-18
d=26.96
w=4.48
+11.39%
|
325/40-18
d=28.24
w=5.12
+16.67%
|
325/45-18
d=29.52
w=5.76
+21.96%
|
325/50-18
d=30.80
w=6.40
+27.25%
|
325/55-18
d=32.07
w=7.04
+32.54%
|
325/60-18
d=33.35
w=7.68
+37.82%
|
325/65-18
d=34.63
w=8.32
+43.11%
|
325/70-18
d=35.91
w=8.96
+48.40%
|
325/75-18
d=37.19
w=9.60
+53.68%
|
325/80-18
d=38.47
w=10.24
+58.97%
|
325/85-18
d=39.75
w=10.88
+64.26%
|
| 335 |
335/25-18
d=24.59
w=3.30
+1.63%
|
335/30-18
d=25.91
w=3.96
+7.08%
|
335/35-18
d=27.23
w=4.62
+12.53%
|
335/40-18
d=28.55
w=5.28
+17.98%
|
335/45-18
d=29.87
w=5.94
+23.43%
|
335/50-18
d=31.19
w=6.59
+28.88%
|
335/55-18
d=32.51
w=7.25
+34.33%
|
335/60-18
d=33.83
w=7.91
+39.78%
|
335/65-18
d=35.15
w=8.57
+45.23%
|
335/70-18
d=36.46
w=9.23
+50.68%
|
335/75-18
d=37.78
w=9.89
+56.12%
|
335/80-18
d=39.10
w=10.55
+61.57%
|
335/85-18
d=40.42
w=11.21
+67.02%
|
|
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!