Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
180/60r18 vs 195/50r18 Tire Comparison Side By Side
  180/60-18 195/50-18 Difference
Diameter inches (mm) 26.5 (673.2) 25.68 (652.2) -0.83 (-21) -3.1%
Width inches (mm) 7.09 (180) 7.68 (195) 0.59 (15) 8.3%
Circum. inches (mm) 83.26 (2114.92) 80.67 (2048.95) -2.6 (-65.97) -3.1%
Sidewall Height inches (mm) 4.25 (108) 3.84 (97.5) -0.41 (-10.5) -9.7%
Revolutions per mile (km) 760.95 (472.83) 785.45 (488.05) 24.5 (15.22) 3.2%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.38 mph (31.18 km/h)
25 mph (40.23 km/h)24.22 mph (38.98 km/h)
30 mph (48.28 km/h)29.06 mph (46.77 km/h)
35 mph (56.33 km/h)33.91 mph (54.57 km/h)
40 mph (64.37 km/h)38.75 mph (62.37 km/h)
45 mph (72.42 km/h)43.6 mph (70.16 km/h)
50 mph (80.47 km/h)48.44 mph (77.96 km/h)
55 mph (88.51 km/h)53.28 mph (85.75 km/h)
60 mph (96.56 km/h)58.13 mph (93.55 km/h)
65 mph (104.61 km/h)62.97 mph (101.34 km/h)
70 mph (112.65 km/h)67.82 mph (109.14 km/h)
75 mph (120.7 km/h)72.66 mph (116.94 km/h)
80 mph (128.75 km/h)77.5 mph (124.73 km/h)
85 mph (136.79 km/h)82.35 mph (132.53 km/h)
90 mph (144.84 km/h)87.19 mph (140.32 km/h)
95 mph (152.89 km/h)92.04 mph (148.12 km/h)
100 mph (160.93 km/h)96.88 mph (155.91 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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