| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 235/55-18 | 0.00 % | 50.00 | 1,000.00 | 28.18 | 5.09 | 129.25 |
| 185/70-18 | +0.07 % | 50.03 | 999.30 | 28.20 | 5.10 | 129.50 |
| 215/60-18 | -0.07 % | 49.97 | 1,000.70 | 28.16 | 5.08 | 129.00 |
| 325/40-18 | +0.21 % | 50.10 | 997.90 | 28.24 | 5.12 | 130.00 |
| 285/45-18 | -0.28 % | 49.86 | 1,002.79 | 28.10 | 5.05 | 128.25 |
| 255/50-18 | -0.49 % | 49.76 | 1,004.89 | 28.04 | 5.02 | 127.50 |
| 175/75-18 | +0.56 % | 50.28 | 994.41 | 28.33 | 5.17 | 131.25 |
| 155/85-18 | +0.70 % | 50.35 | 993.01 | 28.37 | 5.19 | 131.75 |
| 195/65-18 | -0.70 % | 49.65 | 1,006.99 | 27.98 | 4.99 | 126.75 |
| 165/80-18 | +0.77 % | 50.38 | 992.32 | 28.39 | 5.20 | 132.00 |
| 265/50-18 | +0.91 % | 50.45 | 990.92 | 28.43 | 5.22 | 132.50 |
| 315/40-18 | -0.91 % | 49.55 | 1,009.08 | 27.92 | 4.96 | 126.00 |
| 295/45-18 | +0.98 % | 50.49 | 990.22 | 28.45 | 5.23 | 132.75 |
| 205/65-18 | +1.12 % | 50.56 | 988.82 | 28.49 | 5.25 | 133.25 |
| 335/40-18 | +1.33 % | 50.66 | 986.73 | 28.55 | 5.28 | 134.00 |
| 155/80-18 | -1.47 % | 49.27 | 1,014.67 | 27.76 | 4.88 | 124.00 |
| 245/55-18 | +1.54 % | 50.77 | 984.63 | 28.61 | 5.31 | 134.75 |
| 275/45-18 | -1.54 % | 49.23 | 1,015.37 | 27.74 | 4.87 | 123.75 |
| 225/55-18 | -1.54 % | 49.23 | 1,015.37 | 27.74 | 4.87 | 123.75 |
| 165/75-18 | -1.54 % | 49.23 | 1,015.37 | 27.74 | 4.87 | 123.75 |
| 225/60-18 | +1.61 % | 50.80 | 983.93 | 28.63 | 5.31 | 135.00 |
| 145/85-18 | -1.68 % | 49.16 | 1,016.77 | 27.70 | 4.85 | 123.25 |
| 205/60-18 | -1.75 % | 49.13 | 1,017.47 | 27.69 | 4.84 | 123.00 |
| 245/50-18 | -1.89 % | 49.06 | 1,018.86 | 27.65 | 4.82 | 122.50 |
| 175/70-18 | -1.89 % | 49.06 | 1,018.86 | 27.65 | 4.82 | 122.50 |
| 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
-25.99%
|
145/30-18
d=21.43
w=1.71
-23.96%
|
145/35-18
d=22.00
w=2.00
-21.94%
|
145/40-18
d=22.57
w=2.28
-19.91%
|
145/45-18
d=23.14
w=2.57
-17.88%
|
145/50-18
d=23.71
w=2.85
-15.86%
|
145/55-18
d=24.28
w=3.14
-13.83%
|
145/60-18
d=24.85
w=3.43
-11.81%
|
145/65-18
d=25.42
w=3.71
-9.78%
|
145/70-18
d=25.99
w=4.00
-7.75%
|
145/75-18
d=26.56
w=4.28
-5.73%
|
145/80-18
d=27.13
w=4.57
-3.70%
|
145/85-18
d=27.70
w=4.85
-1.68%
|
| 155 |
155/25-18
d=21.05
w=1.53
-25.29%
|
155/30-18
d=21.66
w=1.83
-23.12%
|
155/35-18
d=22.27
w=2.14
-20.96%
|
155/40-18
d=22.88
w=2.44
-18.79%
|
155/45-18
d=23.49
w=2.75
-16.63%
|
155/50-18
d=24.10
w=3.05
-14.46%
|
155/55-18
d=24.71
w=3.36
-12.30%
|
155/60-18
d=25.32
w=3.66
-10.13%
|
155/65-18
d=25.93
w=3.97
-7.96%
|
155/70-18
d=26.54
w=4.27
-5.80%
|
155/75-18
d=27.15
w=4.58
-3.63%
|
155/80-18
d=27.76
w=4.88
-1.47%
|
155/85-18
d=28.37
w=5.19
+0.70%
|
| 165 |
165/25-18
d=21.25
w=1.62
-24.59%
|
165/30-18
d=21.90
w=1.95
-22.29%
|
165/35-18
d=22.55
w=2.27
-19.98%
|
165/40-18
d=23.20
w=2.60
-17.68%
|
165/45-18
d=23.85
w=2.92
-15.37%
|
165/50-18
d=24.50
w=3.25
-13.06%
|
165/55-18
d=25.15
w=3.57
-10.76%
|
165/60-18
d=25.80
w=3.90
-8.45%
|
165/65-18
d=26.44
w=4.22
-6.15%
|
165/70-18
d=27.09
w=4.55
-3.84%
|
165/75-18
d=27.74
w=4.87
-1.54%
|
165/80-18
d=28.39
w=5.20
+0.77%
|
165/85-18
d=29.04
w=5.52
+3.07%
|
| 175 |
175/25-18
d=21.44
w=1.72
-23.89%
|
175/30-18
d=22.13
w=2.07
-21.45%
|
175/35-18
d=22.82
w=2.41
-19.00%
|
175/40-18
d=23.51
w=2.76
-16.56%
|
175/45-18
d=24.20
w=3.10
-14.11%
|
175/50-18
d=24.89
w=3.44
-11.67%
|
175/55-18
d=25.58
w=3.79
-9.22%
|
175/60-18
d=26.27
w=4.13
-6.78%
|
175/65-18
d=26.96
w=4.48
-4.33%
|
175/70-18
d=27.65
w=4.82
-1.89%
|
175/75-18
d=28.33
w=5.17
+0.56%
|
175/80-18
d=29.02
w=5.51
+3.00%
|
175/85-18
d=29.71
w=5.86
+5.45%
|
| 185 |
185/25-18
d=21.64
w=1.82
-23.19%
|
185/30-18
d=22.37
w=2.19
-20.61%
|
185/35-18
d=23.10
w=2.55
-18.02%
|
185/40-18
d=23.83
w=2.91
-15.44%
|
185/45-18
d=24.56
w=3.28
-12.85%
|
185/50-18
d=25.28
w=3.64
-10.27%
|
185/55-18
d=26.01
w=4.01
-7.68%
|
185/60-18
d=26.74
w=4.37
-5.10%
|
185/65-18
d=27.47
w=4.73
-2.52%
|
185/70-18
d=28.20
w=5.10
+0.07%
|
185/75-18
d=28.93
w=5.46
+2.65%
|
185/80-18
d=29.65
w=5.83
+5.24%
|
185/85-18
d=30.38
w=6.19
+7.82%
|
| 195 |
195/25-18
d=21.84
w=1.92
-22.50%
|
195/30-18
d=22.61
w=2.30
-19.77%
|
195/35-18
d=23.37
w=2.69
-17.05%
|
195/40-18
d=24.14
w=3.07
-14.32%
|
195/45-18
d=24.91
w=3.45
-11.60%
|
195/50-18
d=25.68
w=3.84
-8.87%
|
195/55-18
d=26.44
w=4.22
-6.15%
|
195/60-18
d=27.21
w=4.61
-3.42%
|
195/65-18
d=27.98
w=4.99
-0.70%
|
195/70-18
d=28.75
w=5.37
+2.03%
|
195/75-18
d=29.52
w=5.76
+4.75%
|
195/80-18
d=30.28
w=6.14
+7.48%
|
195/85-18
d=31.05
w=6.53
+10.20%
|
| 205 |
205/25-18
d=22.04
w=2.02
-21.80%
|
205/30-18
d=22.84
w=2.42
-18.93%
|
205/35-18
d=23.65
w=2.82
-16.07%
|
205/40-18
d=24.46
w=3.23
-13.20%
|
205/45-18
d=25.26
w=3.63
-10.34%
|
205/50-18
d=26.07
w=4.04
-7.48%
|
205/55-18
d=26.88
w=4.44
-4.61%
|
205/60-18
d=27.69
w=4.84
-1.75%
|
205/65-18
d=28.49
w=5.25
+1.12%
|
205/70-18
d=29.30
w=5.65
+3.98%
|
205/75-18
d=30.11
w=6.05
+6.85%
|
205/80-18
d=30.91
w=6.46
+9.71%
|
205/85-18
d=31.72
w=6.86
+12.58%
|
| 215 |
215/25-18
d=22.23
w=2.12
-21.10%
|
215/30-18
d=23.08
w=2.54
-18.09%
|
215/35-18
d=23.93
w=2.96
-15.09%
|
215/40-18
d=24.77
w=3.39
-12.09%
|
215/45-18
d=25.62
w=3.81
-9.08%
|
215/50-18
d=26.46
w=4.23
-6.08%
|
215/55-18
d=27.31
w=4.66
-3.07%
|
215/60-18
d=28.16
w=5.08
-0.07%
|
215/65-18
d=29.00
w=5.50
+2.93%
|
215/70-18
d=29.85
w=5.93
+5.94%
|
215/75-18
d=30.70
w=6.35
+8.94%
|
215/80-18
d=31.54
w=6.77
+11.95%
|
215/85-18
d=32.39
w=7.19
+14.95%
|
| 225 |
225/25-18
d=22.43
w=2.21
-20.40%
|
225/30-18
d=23.31
w=2.66
-17.26%
|
225/35-18
d=24.20
w=3.10
-14.11%
|
225/40-18
d=25.09
w=3.54
-10.97%
|
225/45-18
d=25.97
w=3.99
-7.82%
|
225/50-18
d=26.86
w=4.43
-4.68%
|
225/55-18
d=27.74
w=4.87
-1.54%
|
225/60-18
d=28.63
w=5.31
+1.61%
|
225/65-18
d=29.52
w=5.76
+4.75%
|
225/70-18
d=30.40
w=6.20
+7.89%
|
225/75-18
d=31.29
w=6.64
+11.04%
|
225/80-18
d=32.17
w=7.09
+14.18%
|
225/85-18
d=33.06
w=7.53
+17.33%
|
| 235 |
235/25-18
d=22.63
w=2.31
-19.70%
|
235/30-18
d=23.55
w=2.78
-16.42%
|
235/35-18
d=24.48
w=3.24
-13.13%
|
235/40-18
d=25.40
w=3.70
-9.85%
|
235/45-18
d=26.33
w=4.16
-6.57%
|
235/50-18
d=27.25
w=4.63
-3.28%
|
235/55-18
d=28.18
w=5.09
0.00%
|
235/60-18
d=29.10
w=5.55
+3.28%
|
235/65-18
d=30.03
w=6.01
+6.57%
|
235/70-18
d=30.95
w=6.48
+9.85%
|
235/75-18
d=31.88
w=6.94
+13.13%
|
235/80-18
d=32.80
w=7.40
+16.42%
|
235/85-18
d=33.73
w=7.86
+19.70%
|
| 245 |
245/25-18
d=22.82
w=2.41
-19.00%
|
245/30-18
d=23.79
w=2.89
-15.58%
|
245/35-18
d=24.75
w=3.38
-12.16%
|
245/40-18
d=25.72
w=3.86
-8.73%
|
245/45-18
d=26.68
w=4.34
-5.31%
|
245/50-18
d=27.65
w=4.82
-1.89%
|
245/55-18
d=28.61
w=5.31
+1.54%
|
245/60-18
d=29.57
w=5.79
+4.96%
|
245/65-18
d=30.54
w=6.27
+8.38%
|
245/70-18
d=31.50
w=6.75
+11.81%
|
245/75-18
d=32.47
w=7.23
+15.23%
|
245/80-18
d=33.43
w=7.72
+18.65%
|
245/85-18
d=34.40
w=8.20
+22.08%
|
| 255 |
255/25-18
d=23.02
w=2.51
-18.30%
|
255/30-18
d=24.02
w=3.01
-14.74%
|
255/35-18
d=25.03
w=3.51
-11.18%
|
255/40-18
d=26.03
w=4.02
-7.61%
|
255/45-18
d=27.04
w=4.52
-4.05%
|
255/50-18
d=28.04
w=5.02
-0.49%
|
255/55-18
d=29.04
w=5.52
+3.07%
|
255/60-18
d=30.05
w=6.02
+6.64%
|
255/65-18
d=31.05
w=6.53
+10.20%
|
255/70-18
d=32.06
w=7.03
+13.76%
|
255/75-18
d=33.06
w=7.53
+17.33%
|
255/80-18
d=34.06
w=8.03
+20.89%
|
255/85-18
d=35.07
w=8.53
+24.45%
|
| 265 |
265/25-18
d=23.22
w=2.61
-17.61%
|
265/30-18
d=24.26
w=3.13
-13.90%
|
265/35-18
d=25.30
w=3.65
-10.20%
|
265/40-18
d=26.35
w=4.17
-6.50%
|
265/45-18
d=27.39
w=4.69
-2.79%
|
265/50-18
d=28.43
w=5.22
+0.91%
|
265/55-18
d=29.48
w=5.74
+4.61%
|
265/60-18
d=30.52
w=6.26
+8.31%
|
265/65-18
d=31.56
w=6.78
+12.02%
|
265/70-18
d=32.61
w=7.30
+15.72%
|
265/75-18
d=33.65
w=7.82
+19.42%
|
265/80-18
d=34.69
w=8.35
+23.12%
|
265/85-18
d=35.74
w=8.87
+26.83%
|
| 275 |
275/25-18
d=23.41
w=2.71
-16.91%
|
275/30-18
d=24.50
w=3.25
-13.06%
|
275/35-18
d=25.58
w=3.79
-9.22%
|
275/40-18
d=26.66
w=4.33
-5.38%
|
275/45-18
d=27.74
w=4.87
-1.54%
|
275/50-18
d=28.83
w=5.41
+2.31%
|
275/55-18
d=29.91
w=5.95
+6.15%
|
275/60-18
d=30.99
w=6.50
+9.99%
|
275/65-18
d=32.07
w=7.04
+13.83%
|
275/70-18
d=33.16
w=7.58
+17.68%
|
275/75-18
d=34.24
w=8.12
+21.52%
|
275/80-18
d=35.32
w=8.66
+25.36%
|
275/85-18
d=36.41
w=9.20
+29.20%
|
| 285 |
285/25-18
d=23.61
w=2.81
-16.21%
|
285/30-18
d=24.73
w=3.37
-12.23%
|
285/35-18
d=25.85
w=3.93
-8.24%
|
285/40-18
d=26.98
w=4.49
-4.26%
|
285/45-18
d=28.10
w=5.05
-0.28%
|
285/50-18
d=29.22
w=5.61
+3.70%
|
285/55-18
d=30.34
w=6.17
+7.68%
|
285/60-18
d=31.46
w=6.73
+11.67%
|
285/65-18
d=32.59
w=7.29
+15.65%
|
285/70-18
d=33.71
w=7.85
+19.63%
|
285/75-18
d=34.83
w=8.42
+23.61%
|
285/80-18
d=35.95
w=8.98
+27.60%
|
285/85-18
d=37.07
w=9.54
+31.58%
|
| 295 |
295/25-18
d=23.81
w=2.90
-15.51%
|
295/30-18
d=24.97
w=3.48
-11.39%
|
295/35-18
d=26.13
w=4.06
-7.27%
|
295/40-18
d=27.29
w=4.65
-3.14%
|
295/45-18
d=28.45
w=5.23
+0.98%
|
295/50-18
d=29.61
w=5.81
+5.10%
|
295/55-18
d=30.78
w=6.39
+9.22%
|
295/60-18
d=31.94
w=6.97
+13.34%
|
295/65-18
d=33.10
w=7.55
+17.47%
|
295/70-18
d=34.26
w=8.13
+21.59%
|
295/75-18
d=35.42
w=8.71
+25.71%
|
295/80-18
d=36.58
w=9.29
+29.83%
|
295/85-18
d=37.74
w=9.87
+33.95%
|
| 305 |
305/25-18
d=24.00
w=3.00
-14.81%
|
305/30-18
d=25.20
w=3.60
-10.55%
|
305/35-18
d=26.41
w=4.20
-6.29%
|
305/40-18
d=27.61
w=4.80
-2.03%
|
305/45-18
d=28.81
w=5.40
+2.24%
|
305/50-18
d=30.01
w=6.00
+6.50%
|
305/55-18
d=31.21
w=6.60
+10.76%
|
305/60-18
d=32.41
w=7.20
+15.02%
|
305/65-18
d=33.61
w=7.81
+19.28%
|
305/70-18
d=34.81
w=8.41
+23.54%
|
305/75-18
d=36.01
w=9.01
+27.80%
|
305/80-18
d=37.21
w=9.61
+32.07%
|
305/85-18
d=38.41
w=10.21
+36.33%
|
| 315 |
315/25-18
d=24.20
w=3.10
-14.11%
|
315/30-18
d=25.44
w=3.72
-9.71%
|
315/35-18
d=26.68
w=4.34
-5.31%
|
315/40-18
d=27.92
w=4.96
-0.91%
|
315/45-18
d=29.16
w=5.58
+3.49%
|
315/50-18
d=30.40
w=6.20
+7.89%
|
315/55-18
d=31.64
w=6.82
+12.30%
|
315/60-18
d=32.88
w=7.44
+16.70%
|
315/65-18
d=34.12
w=8.06
+21.10%
|
315/70-18
d=35.36
w=8.68
+25.50%
|
315/75-18
d=36.60
w=9.30
+29.90%
|
315/80-18
d=37.84
w=9.92
+34.30%
|
315/85-18
d=39.08
w=10.54
+38.70%
|
| 325 |
325/25-18
d=24.40
w=3.20
-13.41%
|
325/30-18
d=25.68
w=3.84
-8.87%
|
325/35-18
d=26.96
w=4.48
-4.33%
|
325/40-18
d=28.24
w=5.12
+0.21%
|
325/45-18
d=29.52
w=5.76
+4.75%
|
325/50-18
d=30.80
w=6.40
+9.29%
|
325/55-18
d=32.07
w=7.04
+13.83%
|
325/60-18
d=33.35
w=7.68
+18.37%
|
325/65-18
d=34.63
w=8.32
+22.91%
|
325/70-18
d=35.91
w=8.96
+27.46%
|
325/75-18
d=37.19
w=9.60
+32.00%
|
325/80-18
d=38.47
w=10.24
+36.54%
|
325/85-18
d=39.75
w=10.88
+41.08%
|
| 335 |
335/25-18
d=24.59
w=3.30
-12.71%
|
335/30-18
d=25.91
w=3.96
-8.03%
|
335/35-18
d=27.23
w=4.62
-3.35%
|
335/40-18
d=28.55
w=5.28
+1.33%
|
335/45-18
d=29.87
w=5.94
+6.01%
|
335/50-18
d=31.19
w=6.59
+10.69%
|
335/55-18
d=32.51
w=7.25
+15.37%
|
335/60-18
d=33.83
w=7.91
+20.05%
|
335/65-18
d=35.15
w=8.57
+24.73%
|
335/70-18
d=36.46
w=9.23
+29.41%
|
335/75-18
d=37.78
w=9.89
+34.09%
|
335/80-18
d=39.10
w=10.55
+38.77%
|
335/85-18
d=40.42
w=11.21
+43.45%
|
|
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!