Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
120/70r15 vs 120/80r14 Tire Comparison Side By Side
  120/70-15 120/80-14 Difference
Diameter inches (mm) 21.61 (549) 21.56 (547.6) -0.06 (-1.4) -0.3%
Width inches (mm) 4.72 (120) 4.72 (120) 0 (0) 0%
Circum. inches (mm) 67.9 (1724.73) 67.73 (1720.34) -0.17 (-4.4) -0.3%
Sidewall Height inches (mm) 3.31 (84) 3.78 (96) 0.47 (12) 14.3%
Revolutions per mile (km) 933.1 (579.8) 935.48 (581.28) 2.39 (1.48) 0.3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.95 mph (32.1 km/h)
25 mph (40.23 km/h)24.94 mph (40.13 km/h)
30 mph (48.28 km/h)29.92 mph (48.16 km/h)
35 mph (56.33 km/h)34.91 mph (56.18 km/h)
40 mph (64.37 km/h)39.9 mph (64.21 km/h)
45 mph (72.42 km/h)44.89 mph (72.24 km/h)
50 mph (80.47 km/h)49.87 mph (80.26 km/h)
55 mph (88.51 km/h)54.86 mph (88.29 km/h)
60 mph (96.56 km/h)59.85 mph (96.31 km/h)
65 mph (104.61 km/h)64.83 mph (104.34 km/h)
70 mph (112.65 km/h)69.82 mph (112.37 km/h)
75 mph (120.7 km/h)74.81 mph (120.39 km/h)
80 mph (128.75 km/h)79.8 mph (128.42 km/h)
85 mph (136.79 km/h)84.78 mph (136.45 km/h)
90 mph (144.84 km/h)89.77 mph (144.47 km/h)
95 mph (152.89 km/h)94.76 mph (152.5 km/h)
100 mph (160.93 km/h)99.74 mph (160.52 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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