Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
255/55r20 vs 255/45r20 Tire Comparison Side By Side
  255/55-20 255/45-20 Difference
Diameter inches (mm) 31.04 (788.5) 29.04 (737.5) -2.01 (-51) -6.5%
Width inches (mm) 10.04 (255) 10.04 (255) 0 (0) 0%
Circum. inches (mm) 97.53 (2477.15) 91.22 (2316.92) -6.31 (-160.22) -6.5%
Sidewall Height inches (mm) 5.52 (140.25) 4.52 (114.75) -1 (-25.5) -18.2%
Revolutions per mile (km) 649.68 (403.69) 694.6 (431.61) 44.93 (27.92) 6.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)18.71 mph (30.11 km/h)
25 mph (40.23 km/h)23.38 mph (37.63 km/h)
30 mph (48.28 km/h)28.06 mph (45.16 km/h)
35 mph (56.33 km/h)32.74 mph (52.68 km/h)
40 mph (64.37 km/h)37.41 mph (60.21 km/h)
45 mph (72.42 km/h)42.09 mph (67.74 km/h)
50 mph (80.47 km/h)46.77 mph (75.26 km/h)
55 mph (88.51 km/h)51.44 mph (82.79 km/h)
60 mph (96.56 km/h)56.12 mph (90.32 km/h)
65 mph (104.61 km/h)60.8 mph (97.84 km/h)
70 mph (112.65 km/h)65.47 mph (105.37 km/h)
75 mph (120.7 km/h)70.15 mph (112.89 km/h)
80 mph (128.75 km/h)74.83 mph (120.42 km/h)
85 mph (136.79 km/h)79.5 mph (127.95 km/h)
90 mph (144.84 km/h)84.18 mph (135.47 km/h)
95 mph (152.89 km/h)88.86 mph (143 km/h)
100 mph (160.93 km/h)93.53 mph (150.53 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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