Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
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100/70r12 vs 90/80r12 Tire Comparison Side By Side
  100/70-12 90/80-12 Difference
Diameter inches (mm) 17.51 (444.8) 17.67 (448.8) 0.16 (4) 0.9%
Width inches (mm) 3.94 (100) 3.54 (90) -0.39 (-10) -10%
Circum. inches (mm) 55.01 (1397.38) 55.51 (1409.95) 0.49 (12.57) 0.9%
Sidewall Height inches (mm) 2.76 (70) 2.83 (72) 0.08 (2) 2.9%
Revolutions per mile (km) 1151.69 (715.62) 1141.42 (709.25) -10.26 (-6.38) -0.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.18 mph (32.48 km/h)
25 mph (40.23 km/h)25.22 mph (40.6 km/h)
30 mph (48.28 km/h)30.27 mph (48.71 km/h)
35 mph (56.33 km/h)35.31 mph (56.83 km/h)
40 mph (64.37 km/h)40.36 mph (64.95 km/h)
45 mph (72.42 km/h)45.4 mph (73.07 km/h)
50 mph (80.47 km/h)50.45 mph (81.19 km/h)
55 mph (88.51 km/h)55.49 mph (89.31 km/h)
60 mph (96.56 km/h)60.54 mph (97.43 km/h)
65 mph (104.61 km/h)65.58 mph (105.55 km/h)
70 mph (112.65 km/h)70.63 mph (113.67 km/h)
75 mph (120.7 km/h)75.67 mph (121.79 km/h)
80 mph (128.75 km/h)80.72 mph (129.91 km/h)
85 mph (136.79 km/h)85.76 mph (138.02 km/h)
90 mph (144.84 km/h)90.81 mph (146.14 km/h)
95 mph (152.89 km/h)95.85 mph (154.26 km/h)
100 mph (160.93 km/h)100.9 mph (162.38 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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