Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
100/100r18 vs 100/90r18 Tire Comparison Side By Side
  100/100-18 100/90-18 Difference
Diameter inches (mm) 25.87 (657.2) 25.09 (637.2) -0.79 (-20) -3%
Width inches (mm) 3.94 (100) 3.94 (100) 0 (0) 0%
Circum. inches (mm) 81.29 (2064.65) 78.81 (2001.82) -2.47 (-62.83) -3%
Sidewall Height inches (mm) 3.94 (100) 3.54 (90) -0.39 (-10) -10%
Revolutions per mile (km) 779.47 (484.34) 803.94 (499.54) 24.47 (15.2) 3.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.39 mph (31.21 km/h)
25 mph (40.23 km/h)24.24 mph (39.01 km/h)
30 mph (48.28 km/h)29.09 mph (46.81 km/h)
35 mph (56.33 km/h)33.93 mph (54.61 km/h)
40 mph (64.37 km/h)38.78 mph (62.41 km/h)
45 mph (72.42 km/h)43.63 mph (70.22 km/h)
50 mph (80.47 km/h)48.48 mph (78.02 km/h)
55 mph (88.51 km/h)53.33 mph (85.82 km/h)
60 mph (96.56 km/h)58.17 mph (93.62 km/h)
65 mph (104.61 km/h)63.02 mph (101.42 km/h)
70 mph (112.65 km/h)67.87 mph (109.23 km/h)
75 mph (120.7 km/h)72.72 mph (117.03 km/h)
80 mph (128.75 km/h)77.57 mph (124.83 km/h)
85 mph (136.79 km/h)82.41 mph (132.63 km/h)
90 mph (144.84 km/h)87.26 mph (140.43 km/h)
95 mph (152.89 km/h)92.11 mph (148.24 km/h)
100 mph (160.93 km/h)96.96 mph (156.04 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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