Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
120/80r14 vs 100/90r14 Tire Comparison Side By Side
  120/80-14 100/90-14 Difference
Diameter inches (mm) 21.56 (547.6) 21.09 (535.6) -0.47 (-12) -2.2%
Width inches (mm) 4.72 (120) 3.94 (100) -0.79 (-20) -16.7%
Circum. inches (mm) 67.73 (1720.34) 66.25 (1682.64) -1.48 (-37.7) -2.2%
Sidewall Height inches (mm) 3.78 (96) 3.54 (90) -0.24 (-6) -6.2%
Revolutions per mile (km) 935.48 (581.28) 956.44 (594.3) 20.96 (13.02) 2.2%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.56 mph (31.48 km/h)
25 mph (40.23 km/h)24.45 mph (39.35 km/h)
30 mph (48.28 km/h)29.34 mph (47.22 km/h)
35 mph (56.33 km/h)34.23 mph (55.09 km/h)
40 mph (64.37 km/h)39.12 mph (62.96 km/h)
45 mph (72.42 km/h)44.01 mph (70.83 km/h)
50 mph (80.47 km/h)48.9 mph (78.7 km/h)
55 mph (88.51 km/h)53.79 mph (86.57 km/h)
60 mph (96.56 km/h)58.69 mph (94.44 km/h)
65 mph (104.61 km/h)63.58 mph (102.32 km/h)
70 mph (112.65 km/h)68.47 mph (110.19 km/h)
75 mph (120.7 km/h)73.36 mph (118.06 km/h)
80 mph (128.75 km/h)78.25 mph (125.93 km/h)
85 mph (136.79 km/h)83.14 mph (133.8 km/h)
90 mph (144.84 km/h)88.03 mph (141.67 km/h)
95 mph (152.89 km/h)92.92 mph (149.54 km/h)
100 mph (160.93 km/h)97.81 mph (157.41 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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