Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
195/40r18 vs 225/40r18 Tire Comparison Side By Side
  195/40-18 225/40-18 Difference
Diameter inches (mm) 24.14 (613.2) 25.09 (637.2) 0.94 (24) 3.9%
Width inches (mm) 7.68 (195) 8.86 (225) 1.18 (30) 15.4%
Circum. inches (mm) 75.84 (1926.42) 78.81 (2001.82) 2.97 (75.4) 3.9%
Sidewall Height inches (mm) 3.07 (78) 3.54 (90) 0.47 (12) 15.4%
Revolutions per mile (km) 835.4 (519.1) 803.94 (499.54) -31.47 (-19.55) -3.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.78 mph (33.45 km/h)
25 mph (40.23 km/h)25.98 mph (41.81 km/h)
30 mph (48.28 km/h)31.17 mph (50.17 km/h)
35 mph (56.33 km/h)36.37 mph (58.53 km/h)
40 mph (64.37 km/h)41.57 mph (66.89 km/h)
45 mph (72.42 km/h)46.76 mph (75.26 km/h)
50 mph (80.47 km/h)51.96 mph (83.62 km/h)
55 mph (88.51 km/h)57.15 mph (91.98 km/h)
60 mph (96.56 km/h)62.35 mph (100.34 km/h)
65 mph (104.61 km/h)67.54 mph (108.7 km/h)
70 mph (112.65 km/h)72.74 mph (117.06 km/h)
75 mph (120.7 km/h)77.94 mph (125.43 km/h)
80 mph (128.75 km/h)83.13 mph (133.79 km/h)
85 mph (136.79 km/h)88.33 mph (142.15 km/h)
90 mph (144.84 km/h)93.52 mph (150.51 km/h)
95 mph (152.89 km/h)98.72 mph (158.87 km/h)
100 mph (160.93 km/h)103.91 mph (167.23 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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