Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
100/100r12 vs 120/70r12 Tire Comparison Side By Side
  100/100-12 120/70-12 Difference
Diameter inches (mm) 19.87 (504.8) 18.61 (472.8) -1.26 (-32) -6.3%
Width inches (mm) 3.94 (100) 4.72 (120) 0.79 (20) 20%
Circum. inches (mm) 62.44 (1585.88) 58.48 (1485.35) -3.96 (-100.53) -6.3%
Sidewall Height inches (mm) 3.94 (100) 3.31 (84) -0.63 (-16) -16%
Revolutions per mile (km) 1014.8 (630.57) 1083.48 (673.24) 68.68 (42.68) 6.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)18.73 mph (30.15 km/h)
25 mph (40.23 km/h)23.42 mph (37.68 km/h)
30 mph (48.28 km/h)28.1 mph (45.22 km/h)
35 mph (56.33 km/h)32.78 mph (52.76 km/h)
40 mph (64.37 km/h)37.46 mph (60.29 km/h)
45 mph (72.42 km/h)42.15 mph (67.83 km/h)
50 mph (80.47 km/h)46.83 mph (75.37 km/h)
55 mph (88.51 km/h)51.51 mph (82.9 km/h)
60 mph (96.56 km/h)56.2 mph (90.44 km/h)
65 mph (104.61 km/h)60.88 mph (97.98 km/h)
70 mph (112.65 km/h)65.56 mph (105.51 km/h)
75 mph (120.7 km/h)70.25 mph (113.05 km/h)
80 mph (128.75 km/h)74.93 mph (120.59 km/h)
85 mph (136.79 km/h)79.61 mph (128.12 km/h)
90 mph (144.84 km/h)84.29 mph (135.66 km/h)
95 mph (152.89 km/h)88.98 mph (143.2 km/h)
100 mph (160.93 km/h)93.66 mph (150.73 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
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
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