Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
165/70r12 vs 145/70r13 Tire Comparison Side By Side
  165/70-12 145/70-13 Difference
Diameter inches (mm) 21.09 (535.8) 20.99 (533.2) -0.1 (-2.6) -0.5%
Width inches (mm) 6.5 (165) 5.71 (145) -0.79 (-20) -12.1%
Circum. inches (mm) 66.27 (1683.27) 65.95 (1675.1) -0.32 (-8.17) -0.5%
Sidewall Height inches (mm) 4.55 (115.5) 4 (101.5) -0.55 (-14) -12.1%
Revolutions per mile (km) 956.08 (594.08) 960.75 (596.98) 4.66 (2.9) 0.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.9 mph (32.03 km/h)
25 mph (40.23 km/h)24.88 mph (40.04 km/h)
30 mph (48.28 km/h)29.85 mph (48.05 km/h)
35 mph (56.33 km/h)34.83 mph (56.05 km/h)
40 mph (64.37 km/h)39.81 mph (64.06 km/h)
45 mph (72.42 km/h)44.78 mph (72.07 km/h)
50 mph (80.47 km/h)49.76 mph (80.08 km/h)
55 mph (88.51 km/h)54.73 mph (88.08 km/h)
60 mph (96.56 km/h)59.71 mph (96.09 km/h)
65 mph (104.61 km/h)64.68 mph (104.1 km/h)
70 mph (112.65 km/h)69.66 mph (112.11 km/h)
75 mph (120.7 km/h)74.64 mph (120.12 km/h)
80 mph (128.75 km/h)79.61 mph (128.12 km/h)
85 mph (136.79 km/h)84.59 mph (136.13 km/h)
90 mph (144.84 km/h)89.56 mph (144.14 km/h)
95 mph (152.89 km/h)94.54 mph (152.15 km/h)
100 mph (160.93 km/h)99.51 mph (160.15 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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