| Code | Difference | = 50mph | 1000miles = | Diameter | Wall,in | Wall,mm |
|---|---|---|---|---|---|---|
| 285/65-18 | 0.00 % | 50.00 | 1,000.00 | 32.59 | 7.29 | 185.25 |
| 265/70-18 | +0.06 % | 50.03 | 999.40 | 32.61 | 7.30 | 185.50 |
| 335/55-18 | -0.24 % | 49.88 | 1,002.42 | 32.51 | 7.25 | 184.25 |
| 245/75-18 | -0.36 % | 49.82 | 1,003.62 | 32.47 | 7.23 | 183.75 |
| 305/60-18 | -0.54 % | 49.73 | 1,005.44 | 32.41 | 7.20 | 183.00 |
| 215/85-18 | -0.60 % | 49.70 | 1,006.04 | 32.39 | 7.19 | 182.75 |
| 235/80-18 | +0.66 % | 50.33 | 993.36 | 32.80 | 7.40 | 188.00 |
| 315/60-18 | +0.91 % | 50.45 | 990.94 | 32.88 | 7.44 | 189.00 |
| 225/80-18 | -1.27 % | 49.37 | 1,012.69 | 32.17 | 7.09 | 180.00 |
| 255/75-18 | +1.45 % | 50.72 | 985.50 | 33.06 | 7.53 | 191.25 |
| 225/85-18 | +1.45 % | 50.72 | 985.50 | 33.06 | 7.53 | 191.25 |
| 295/65-18 | +1.57 % | 50.79 | 984.29 | 33.10 | 7.55 | 191.75 |
| 325/55-18 | -1.57 % | 49.21 | 1,015.71 | 32.07 | 7.04 | 178.75 |
| 275/65-18 | -1.57 % | 49.21 | 1,015.71 | 32.07 | 7.04 | 178.75 |
| 255/70-18 | -1.63 % | 49.18 | 1,016.31 | 32.06 | 7.03 | 178.50 |
| 275/70-18 | +1.75 % | 50.88 | 982.48 | 33.16 | 7.58 | 192.50 |
| 295/60-18 | -1.99 % | 49.00 | 1,019.93 | 31.94 | 6.97 | 177.00 |
| 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
-36.00%
|
145/30-18
d=21.43
w=1.71
-34.25%
|
145/35-18
d=22.00
w=2.00
-32.50%
|
145/40-18
d=22.57
w=2.28
-30.75%
|
145/45-18
d=23.14
w=2.57
-29.00%
|
145/50-18
d=23.71
w=2.85
-27.24%
|
145/55-18
d=24.28
w=3.14
-25.49%
|
145/60-18
d=24.85
w=3.43
-23.74%
|
145/65-18
d=25.42
w=3.71
-21.99%
|
145/70-18
d=25.99
w=4.00
-20.24%
|
145/75-18
d=26.56
w=4.28
-18.48%
|
145/80-18
d=27.13
w=4.57
-16.73%
|
145/85-18
d=27.70
w=4.85
-14.98%
|
| 155 |
155/25-18
d=21.05
w=1.53
-35.40%
|
155/30-18
d=21.66
w=1.83
-33.53%
|
155/35-18
d=22.27
w=2.14
-31.65%
|
155/40-18
d=22.88
w=2.44
-29.78%
|
155/45-18
d=23.49
w=2.75
-27.91%
|
155/50-18
d=24.10
w=3.05
-26.04%
|
155/55-18
d=24.71
w=3.36
-24.16%
|
155/60-18
d=25.32
w=3.66
-22.29%
|
155/65-18
d=25.93
w=3.97
-20.42%
|
155/70-18
d=26.54
w=4.27
-18.55%
|
155/75-18
d=27.15
w=4.58
-16.67%
|
155/80-18
d=27.76
w=4.88
-14.80%
|
155/85-18
d=28.37
w=5.19
-12.93%
|
| 165 |
165/25-18
d=21.25
w=1.62
-34.80%
|
165/30-18
d=21.90
w=1.95
-32.80%
|
165/35-18
d=22.55
w=2.27
-30.81%
|
165/40-18
d=23.20
w=2.60
-28.81%
|
165/45-18
d=23.85
w=2.92
-26.82%
|
165/50-18
d=24.50
w=3.25
-24.83%
|
165/55-18
d=25.15
w=3.57
-22.83%
|
165/60-18
d=25.80
w=3.90
-20.84%
|
165/65-18
d=26.44
w=4.22
-18.85%
|
165/70-18
d=27.09
w=4.55
-16.85%
|
165/75-18
d=27.74
w=4.87
-14.86%
|
165/80-18
d=28.39
w=5.20
-12.87%
|
165/85-18
d=29.04
w=5.52
-10.87%
|
| 175 |
175/25-18
d=21.44
w=1.72
-34.19%
|
175/30-18
d=22.13
w=2.07
-32.08%
|
175/35-18
d=22.82
w=2.41
-29.96%
|
175/40-18
d=23.51
w=2.76
-27.85%
|
175/45-18
d=24.20
w=3.10
-25.73%
|
175/50-18
d=24.89
w=3.44
-23.62%
|
175/55-18
d=25.58
w=3.79
-21.51%
|
175/60-18
d=26.27
w=4.13
-19.39%
|
175/65-18
d=26.96
w=4.48
-17.28%
|
175/70-18
d=27.65
w=4.82
-15.16%
|
175/75-18
d=28.33
w=5.17
-13.05%
|
175/80-18
d=29.02
w=5.51
-10.93%
|
175/85-18
d=29.71
w=5.86
-8.82%
|
| 185 |
185/25-18
d=21.64
w=1.82
-33.59%
|
185/30-18
d=22.37
w=2.19
-31.35%
|
185/35-18
d=23.10
w=2.55
-29.12%
|
185/40-18
d=23.83
w=2.91
-26.88%
|
185/45-18
d=24.56
w=3.28
-24.65%
|
185/50-18
d=25.28
w=3.64
-22.41%
|
185/55-18
d=26.01
w=4.01
-20.18%
|
185/60-18
d=26.74
w=4.37
-17.94%
|
185/65-18
d=27.47
w=4.73
-15.71%
|
185/70-18
d=28.20
w=5.10
-13.47%
|
185/75-18
d=28.93
w=5.46
-11.24%
|
185/80-18
d=29.65
w=5.83
-9.00%
|
185/85-18
d=30.38
w=6.19
-6.77%
|
| 195 |
195/25-18
d=21.84
w=1.92
-32.98%
|
195/30-18
d=22.61
w=2.30
-30.63%
|
195/35-18
d=23.37
w=2.69
-28.27%
|
195/40-18
d=24.14
w=3.07
-25.92%
|
195/45-18
d=24.91
w=3.45
-23.56%
|
195/50-18
d=25.68
w=3.84
-21.20%
|
195/55-18
d=26.44
w=4.22
-18.85%
|
195/60-18
d=27.21
w=4.61
-16.49%
|
195/65-18
d=27.98
w=4.99
-14.14%
|
195/70-18
d=28.75
w=5.37
-11.78%
|
195/75-18
d=29.52
w=5.76
-9.42%
|
195/80-18
d=30.28
w=6.14
-7.07%
|
195/85-18
d=31.05
w=6.53
-4.71%
|
| 205 |
205/25-18
d=22.04
w=2.02
-32.38%
|
205/30-18
d=22.84
w=2.42
-29.90%
|
205/35-18
d=23.65
w=2.82
-27.43%
|
205/40-18
d=24.46
w=3.23
-24.95%
|
205/45-18
d=25.26
w=3.63
-22.47%
|
205/50-18
d=26.07
w=4.04
-20.00%
|
205/55-18
d=26.88
w=4.44
-17.52%
|
205/60-18
d=27.69
w=4.84
-15.04%
|
205/65-18
d=28.49
w=5.25
-12.56%
|
205/70-18
d=29.30
w=5.65
-10.09%
|
205/75-18
d=30.11
w=6.05
-7.61%
|
205/80-18
d=30.91
w=6.46
-5.13%
|
205/85-18
d=31.72
w=6.86
-2.66%
|
| 215 |
215/25-18
d=22.23
w=2.12
-31.77%
|
215/30-18
d=23.08
w=2.54
-29.18%
|
215/35-18
d=23.93
w=2.96
-26.58%
|
215/40-18
d=24.77
w=3.39
-23.98%
|
215/45-18
d=25.62
w=3.81
-21.38%
|
215/50-18
d=26.46
w=4.23
-18.79%
|
215/55-18
d=27.31
w=4.66
-16.19%
|
215/60-18
d=28.16
w=5.08
-13.59%
|
215/65-18
d=29.00
w=5.50
-10.99%
|
215/70-18
d=29.85
w=5.93
-8.40%
|
215/75-18
d=30.70
w=6.35
-5.80%
|
215/80-18
d=31.54
w=6.77
-3.20%
|
215/85-18
d=32.39
w=7.19
-0.60%
|
| 225 |
225/25-18
d=22.43
w=2.21
-31.17%
|
225/30-18
d=23.31
w=2.66
-28.45%
|
225/35-18
d=24.20
w=3.10
-25.73%
|
225/40-18
d=25.09
w=3.54
-23.02%
|
225/45-18
d=25.97
w=3.99
-20.30%
|
225/50-18
d=26.86
w=4.43
-17.58%
|
225/55-18
d=27.74
w=4.87
-14.86%
|
225/60-18
d=28.63
w=5.31
-12.14%
|
225/65-18
d=29.52
w=5.76
-9.42%
|
225/70-18
d=30.40
w=6.20
-6.71%
|
225/75-18
d=31.29
w=6.64
-3.99%
|
225/80-18
d=32.17
w=7.09
-1.27%
|
225/85-18
d=33.06
w=7.53
+1.45%
|
| 235 |
235/25-18
d=22.63
w=2.31
-30.57%
|
235/30-18
d=23.55
w=2.78
-27.73%
|
235/35-18
d=24.48
w=3.24
-24.89%
|
235/40-18
d=25.40
w=3.70
-22.05%
|
235/45-18
d=26.33
w=4.16
-19.21%
|
235/50-18
d=27.25
w=4.63
-16.37%
|
235/55-18
d=28.18
w=5.09
-13.53%
|
235/60-18
d=29.10
w=5.55
-10.69%
|
235/65-18
d=30.03
w=6.01
-7.85%
|
235/70-18
d=30.95
w=6.48
-5.01%
|
235/75-18
d=31.88
w=6.94
-2.17%
|
235/80-18
d=32.80
w=7.40
+0.66%
|
235/85-18
d=33.73
w=7.86
+3.50%
|
| 245 |
245/25-18
d=22.82
w=2.41
-29.96%
|
245/30-18
d=23.79
w=2.89
-27.00%
|
245/35-18
d=24.75
w=3.38
-24.04%
|
245/40-18
d=25.72
w=3.86
-21.08%
|
245/45-18
d=26.68
w=4.34
-18.12%
|
245/50-18
d=27.65
w=4.82
-15.16%
|
245/55-18
d=28.61
w=5.31
-12.20%
|
245/60-18
d=29.57
w=5.79
-9.24%
|
245/65-18
d=30.54
w=6.27
-6.28%
|
245/70-18
d=31.50
w=6.75
-3.32%
|
245/75-18
d=32.47
w=7.23
-0.36%
|
245/80-18
d=33.43
w=7.72
+2.60%
|
245/85-18
d=34.40
w=8.20
+5.56%
|
| 255 |
255/25-18
d=23.02
w=2.51
-29.36%
|
255/30-18
d=24.02
w=3.01
-26.28%
|
255/35-18
d=25.03
w=3.51
-23.20%
|
255/40-18
d=26.03
w=4.02
-20.12%
|
255/45-18
d=27.04
w=4.52
-17.04%
|
255/50-18
d=28.04
w=5.02
-13.95%
|
255/55-18
d=29.04
w=5.52
-10.87%
|
255/60-18
d=30.05
w=6.02
-7.79%
|
255/65-18
d=31.05
w=6.53
-4.71%
|
255/70-18
d=32.06
w=7.03
-1.63%
|
255/75-18
d=33.06
w=7.53
+1.45%
|
255/80-18
d=34.06
w=8.03
+4.53%
|
255/85-18
d=35.07
w=8.53
+7.61%
|
| 265 |
265/25-18
d=23.22
w=2.61
-28.75%
|
265/30-18
d=24.26
w=3.13
-25.55%
|
265/35-18
d=25.30
w=3.65
-22.35%
|
265/40-18
d=26.35
w=4.17
-19.15%
|
265/45-18
d=27.39
w=4.69
-15.95%
|
265/50-18
d=28.43
w=5.22
-12.75%
|
265/55-18
d=29.48
w=5.74
-9.54%
|
265/60-18
d=30.52
w=6.26
-6.34%
|
265/65-18
d=31.56
w=6.78
-3.14%
|
265/70-18
d=32.61
w=7.30
+0.06%
|
265/75-18
d=33.65
w=7.82
+3.26%
|
265/80-18
d=34.69
w=8.35
+6.46%
|
265/85-18
d=35.74
w=8.87
+9.67%
|
| 275 |
275/25-18
d=23.41
w=2.71
-28.15%
|
275/30-18
d=24.50
w=3.25
-24.83%
|
275/35-18
d=25.58
w=3.79
-21.51%
|
275/40-18
d=26.66
w=4.33
-18.18%
|
275/45-18
d=27.74
w=4.87
-14.86%
|
275/50-18
d=28.83
w=5.41
-11.54%
|
275/55-18
d=29.91
w=5.95
-8.22%
|
275/60-18
d=30.99
w=6.50
-4.89%
|
275/65-18
d=32.07
w=7.04
-1.57%
|
275/70-18
d=33.16
w=7.58
+1.75%
|
275/75-18
d=34.24
w=8.12
+5.07%
|
275/80-18
d=35.32
w=8.66
+8.40%
|
275/85-18
d=36.41
w=9.20
+11.72%
|
| 285 |
285/25-18
d=23.61
w=2.81
-27.55%
|
285/30-18
d=24.73
w=3.37
-24.10%
|
285/35-18
d=25.85
w=3.93
-20.66%
|
285/40-18
d=26.98
w=4.49
-17.22%
|
285/45-18
d=28.10
w=5.05
-13.77%
|
285/50-18
d=29.22
w=5.61
-10.33%
|
285/55-18
d=30.34
w=6.17
-6.89%
|
285/60-18
d=31.46
w=6.73
-3.44%
|
285/65-18
d=32.59
w=7.29
0.00%
|
285/70-18
d=33.71
w=7.85
+3.44%
|
285/75-18
d=34.83
w=8.42
+6.89%
|
285/80-18
d=35.95
w=8.98
+10.33%
|
285/85-18
d=37.07
w=9.54
+13.77%
|
| 295 |
295/25-18
d=23.81
w=2.90
-26.94%
|
295/30-18
d=24.97
w=3.48
-23.38%
|
295/35-18
d=26.13
w=4.06
-19.81%
|
295/40-18
d=27.29
w=4.65
-16.25%
|
295/45-18
d=28.45
w=5.23
-12.69%
|
295/50-18
d=29.61
w=5.81
-9.12%
|
295/55-18
d=30.78
w=6.39
-5.56%
|
295/60-18
d=31.94
w=6.97
-1.99%
|
295/65-18
d=33.10
w=7.55
+1.57%
|
295/70-18
d=34.26
w=8.13
+5.13%
|
295/75-18
d=35.42
w=8.71
+8.70%
|
295/80-18
d=36.58
w=9.29
+12.26%
|
295/85-18
d=37.74
w=9.87
+15.83%
|
| 305 |
305/25-18
d=24.00
w=3.00
-26.34%
|
305/30-18
d=25.20
w=3.60
-22.65%
|
305/35-18
d=26.41
w=4.20
-18.97%
|
305/40-18
d=27.61
w=4.80
-15.28%
|
305/45-18
d=28.81
w=5.40
-11.60%
|
305/50-18
d=30.01
w=6.00
-7.91%
|
305/55-18
d=31.21
w=6.60
-4.23%
|
305/60-18
d=32.41
w=7.20
-0.54%
|
305/65-18
d=33.61
w=7.81
+3.14%
|
305/70-18
d=34.81
w=8.41
+6.83%
|
305/75-18
d=36.01
w=9.01
+10.51%
|
305/80-18
d=37.21
w=9.61
+14.20%
|
305/85-18
d=38.41
w=10.21
+17.88%
|
| 315 |
315/25-18
d=24.20
w=3.10
-25.73%
|
315/30-18
d=25.44
w=3.72
-21.93%
|
315/35-18
d=26.68
w=4.34
-18.12%
|
315/40-18
d=27.92
w=4.96
-14.32%
|
315/45-18
d=29.16
w=5.58
-10.51%
|
315/50-18
d=30.40
w=6.20
-6.71%
|
315/55-18
d=31.64
w=6.82
-2.90%
|
315/60-18
d=32.88
w=7.44
+0.91%
|
315/65-18
d=34.12
w=8.06
+4.71%
|
315/70-18
d=35.36
w=8.68
+8.52%
|
315/75-18
d=36.60
w=9.30
+12.32%
|
315/80-18
d=37.84
w=9.92
+16.13%
|
315/85-18
d=39.08
w=10.54
+19.93%
|
| 325 |
325/25-18
d=24.40
w=3.20
-25.13%
|
325/30-18
d=25.68
w=3.84
-21.20%
|
325/35-18
d=26.96
w=4.48
-17.28%
|
325/40-18
d=28.24
w=5.12
-13.35%
|
325/45-18
d=29.52
w=5.76
-9.42%
|
325/50-18
d=30.80
w=6.40
-5.50%
|
325/55-18
d=32.07
w=7.04
-1.57%
|
325/60-18
d=33.35
w=7.68
+2.36%
|
325/65-18
d=34.63
w=8.32
+6.28%
|
325/70-18
d=35.91
w=8.96
+10.21%
|
325/75-18
d=37.19
w=9.60
+14.14%
|
325/80-18
d=38.47
w=10.24
+18.06%
|
325/85-18
d=39.75
w=10.88
+21.99%
|
| 335 |
335/25-18
d=24.59
w=3.30
-24.53%
|
335/30-18
d=25.91
w=3.96
-20.48%
|
335/35-18
d=27.23
w=4.62
-16.43%
|
335/40-18
d=28.55
w=5.28
-12.38%
|
335/45-18
d=29.87
w=5.94
-8.34%
|
335/50-18
d=31.19
w=6.59
-4.29%
|
335/55-18
d=32.51
w=7.25
-0.24%
|
335/60-18
d=33.83
w=7.91
+3.81%
|
335/65-18
d=35.15
w=8.57
+7.85%
|
335/70-18
d=36.46
w=9.23
+11.90%
|
335/75-18
d=37.78
w=9.89
+15.95%
|
335/80-18
d=39.10
w=10.55
+20.00%
|
335/85-18
d=40.42
w=11.21
+24.04%
|
|
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!