Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/70r13 vs 175/80r13 Tire Comparison Side By Side
  185/70-13 175/80-13 Difference
Diameter inches (mm) 23.2 (589.2) 24.02 (610.2) 0.83 (21) 3.6%
Width inches (mm) 7.28 (185) 6.89 (175) -0.39 (-10) -5.4%
Circum. inches (mm) 72.88 (1851.03) 75.47 (1917) 2.6 (65.97) 3.6%
Sidewall Height inches (mm) 5.1 (129.5) 5.51 (140) 0.41 (10.5) 8.1%
Revolutions per mile (km) 869.43 (540.24) 839.51 (521.65) -29.92 (-18.59) -3.4%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.71 mph (33.33 km/h)
25 mph (40.23 km/h)25.89 mph (41.67 km/h)
30 mph (48.28 km/h)31.07 mph (50 km/h)
35 mph (56.33 km/h)36.25 mph (58.33 km/h)
40 mph (64.37 km/h)41.43 mph (66.67 km/h)
45 mph (72.42 km/h)46.6 mph (75 km/h)
50 mph (80.47 km/h)51.78 mph (83.34 km/h)
55 mph (88.51 km/h)56.96 mph (91.67 km/h)
60 mph (96.56 km/h)62.14 mph (100 km/h)
65 mph (104.61 km/h)67.32 mph (108.34 km/h)
70 mph (112.65 km/h)72.49 mph (116.67 km/h)
75 mph (120.7 km/h)77.67 mph (125 km/h)
80 mph (128.75 km/h)82.85 mph (133.34 km/h)
85 mph (136.79 km/h)88.03 mph (141.67 km/h)
90 mph (144.84 km/h)93.21 mph (150 km/h)
95 mph (152.89 km/h)98.39 mph (158.34 km/h)
100 mph (160.93 km/h)103.56 mph (166.67 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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