Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
125/80r17 vs 125/70r18 Tire Comparison Side By Side
  125/80-17 125/70-18 Difference
Diameter inches (mm) 24.87 (631.8) 24.89 (632.2) 0.02 (0.4) 0.1%
Width inches (mm) 4.92 (125) 4.92 (125) 0 (0) 0%
Circum. inches (mm) 78.14 (1984.86) 78.19 (1986.11) 0.05 (1.26) 0.1%
Sidewall Height inches (mm) 3.94 (100) 3.44 (87.5) -0.49 (-12.5) -12.5%
Revolutions per mile (km) 810.81 (503.81) 810.3 (503.49) -0.51 (-0.32) -0.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.01 mph (32.21 km/h)
25 mph (40.23 km/h)25.02 mph (40.26 km/h)
30 mph (48.28 km/h)30.02 mph (48.31 km/h)
35 mph (56.33 km/h)35.02 mph (56.36 km/h)
40 mph (64.37 km/h)40.03 mph (64.41 km/h)
45 mph (72.42 km/h)45.03 mph (72.47 km/h)
50 mph (80.47 km/h)50.03 mph (80.52 km/h)
55 mph (88.51 km/h)55.03 mph (88.57 km/h)
60 mph (96.56 km/h)60.04 mph (96.62 km/h)
65 mph (104.61 km/h)65.04 mph (104.67 km/h)
70 mph (112.65 km/h)70.04 mph (112.73 km/h)
75 mph (120.7 km/h)75.05 mph (120.78 km/h)
80 mph (128.75 km/h)80.05 mph (128.83 km/h)
85 mph (136.79 km/h)85.05 mph (136.88 km/h)
90 mph (144.84 km/h)90.06 mph (144.93 km/h)
95 mph (152.89 km/h)95.06 mph (152.98 km/h)
100 mph (160.93 km/h)100.06 mph (161.04 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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