Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
135/80r12 vs 145/55r14 Tire Comparison Side By Side
  135/80-12 145/55-14 Difference
Diameter inches (mm) 20.5 (520.8) 20.28 (515.1) -0.22 (-5.7) -1.1%
Width inches (mm) 5.31 (135) 5.71 (145) 0.39 (10) 7.4%
Circum. inches (mm) 64.42 (1636.14) 63.71 (1618.23) -0.71 (-17.91) -1.1%
Sidewall Height inches (mm) 4.25 (108) 3.14 (79.75) -1.11 (-28.25) -26.2%
Revolutions per mile (km) 983.62 (611.19) 994.51 (617.96) 10.88 (6.76) 1.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.78 mph (31.83 km/h)
25 mph (40.23 km/h)24.73 mph (39.79 km/h)
30 mph (48.28 km/h)29.67 mph (47.75 km/h)
35 mph (56.33 km/h)34.62 mph (55.71 km/h)
40 mph (64.37 km/h)39.56 mph (63.67 km/h)
45 mph (72.42 km/h)44.51 mph (71.63 km/h)
50 mph (80.47 km/h)49.45 mph (79.59 km/h)
55 mph (88.51 km/h)54.4 mph (87.55 km/h)
60 mph (96.56 km/h)59.34 mph (95.5 km/h)
65 mph (104.61 km/h)64.29 mph (103.46 km/h)
70 mph (112.65 km/h)69.23 mph (111.42 km/h)
75 mph (120.7 km/h)74.18 mph (119.38 km/h)
80 mph (128.75 km/h)79.12 mph (127.34 km/h)
85 mph (136.79 km/h)84.07 mph (135.3 km/h)
90 mph (144.84 km/h)89.01 mph (143.26 km/h)
95 mph (152.89 km/h)93.96 mph (151.21 km/h)
100 mph (160.93 km/h)98.91 mph (159.17 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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