Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
255/45r18 vs 255/55r18 Tire Comparison Side By Side
  255/45-18 255/55-18 Difference
Diameter inches (mm) 27.04 (686.7) 29.04 (737.7) 2.01 (51) 7.4%
Width inches (mm) 10.04 (255) 10.04 (255) 0 (0) 0%
Circum. inches (mm) 84.93 (2157.33) 91.24 (2317.55) 6.31 (160.22) 7.4%
Sidewall Height inches (mm) 4.52 (114.75) 5.52 (140.25) 1 (25.5) 22.2%
Revolutions per mile (km) 745.99 (463.53) 694.42 (431.49) -51.57 (-32.05) -6.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.49 mph (34.58 km/h)
25 mph (40.23 km/h)26.86 mph (43.22 km/h)
30 mph (48.28 km/h)32.23 mph (51.87 km/h)
35 mph (56.33 km/h)37.6 mph (60.51 km/h)
40 mph (64.37 km/h)42.97 mph (69.15 km/h)
45 mph (72.42 km/h)48.34 mph (77.8 km/h)
50 mph (80.47 km/h)53.71 mph (86.44 km/h)
55 mph (88.51 km/h)59.08 mph (95.09 km/h)
60 mph (96.56 km/h)64.46 mph (103.73 km/h)
65 mph (104.61 km/h)69.83 mph (112.38 km/h)
70 mph (112.65 km/h)75.2 mph (121.02 km/h)
75 mph (120.7 km/h)80.57 mph (129.67 km/h)
80 mph (128.75 km/h)85.94 mph (138.31 km/h)
85 mph (136.79 km/h)91.31 mph (146.95 km/h)
90 mph (144.84 km/h)96.68 mph (155.6 km/h)
95 mph (152.89 km/h)102.06 mph (164.24 km/h)
100 mph (160.93 km/h)107.43 mph (172.89 km/h)

Gear Ratio / RPMs for New Tire (@ 65 mph)
2.35 2.73 2.94 3.07 3.21 3.31 3.42 3.55 3.73 3.91 4.11 4.27 4.56 4.88 5.13 5.29 5.38 5.71 6.17 7.17
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Most Popular 255/45-R18 Comparisons

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