Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
100/90r18 vs 90/90r18 Tire Comparison Side By Side
  100/90-18 90/90-18 Difference
Diameter inches (mm) 25.09 (637.2) 24.38 (619.2) -0.71 (-18) -2.8%
Width inches (mm) 3.94 (100) 3.54 (90) -0.39 (-10) -10%
Circum. inches (mm) 78.81 (2001.82) 76.59 (1945.27) -2.23 (-56.55) -2.8%
Sidewall Height inches (mm) 3.54 (90) 3.19 (81) -0.35 (-9) -10%
Revolutions per mile (km) 803.94 (499.54) 827.31 (514.07) 23.37 (14.52) 2.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.44 mph (31.28 km/h)
25 mph (40.23 km/h)24.29 mph (39.1 km/h)
30 mph (48.28 km/h)29.15 mph (46.92 km/h)
35 mph (56.33 km/h)34.01 mph (54.74 km/h)
40 mph (64.37 km/h)38.87 mph (62.56 km/h)
45 mph (72.42 km/h)43.73 mph (70.37 km/h)
50 mph (80.47 km/h)48.59 mph (78.19 km/h)
55 mph (88.51 km/h)53.45 mph (86.01 km/h)
60 mph (96.56 km/h)58.31 mph (93.83 km/h)
65 mph (104.61 km/h)63.16 mph (101.65 km/h)
70 mph (112.65 km/h)68.02 mph (109.47 km/h)
75 mph (120.7 km/h)72.88 mph (117.29 km/h)
80 mph (128.75 km/h)77.74 mph (125.11 km/h)
85 mph (136.79 km/h)82.6 mph (132.93 km/h)
90 mph (144.84 km/h)87.46 mph (140.75 km/h)
95 mph (152.89 km/h)92.32 mph (148.57 km/h)
100 mph (160.93 km/h)97.18 mph (156.39 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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