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 245/40r18 Tire Comparison Side By Side
  195/40-18 245/40-18 Difference
Diameter inches (mm) 24.14 (613.2) 25.72 (653.2) 1.57 (40) 6.5%
Width inches (mm) 7.68 (195) 9.65 (245) 1.97 (50) 25.6%
Circum. inches (mm) 75.84 (1926.42) 80.79 (2052.09) 4.95 (125.66) 6.5%
Sidewall Height inches (mm) 3.07 (78) 3.86 (98) 0.79 (20) 25.6%
Revolutions per mile (km) 835.4 (519.1) 784.25 (487.31) -51.16 (-31.79) -6.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.3 mph (34.29 km/h)
25 mph (40.23 km/h)26.63 mph (42.86 km/h)
30 mph (48.28 km/h)31.96 mph (51.43 km/h)
35 mph (56.33 km/h)37.28 mph (60 km/h)
40 mph (64.37 km/h)42.61 mph (68.57 km/h)
45 mph (72.42 km/h)47.94 mph (77.14 km/h)
50 mph (80.47 km/h)53.26 mph (85.72 km/h)
55 mph (88.51 km/h)58.59 mph (94.29 km/h)
60 mph (96.56 km/h)63.91 mph (102.86 km/h)
65 mph (104.61 km/h)69.24 mph (111.43 km/h)
70 mph (112.65 km/h)74.57 mph (120 km/h)
75 mph (120.7 km/h)79.89 mph (128.57 km/h)
80 mph (128.75 km/h)85.22 mph (137.15 km/h)
85 mph (136.79 km/h)90.54 mph (145.72 km/h)
90 mph (144.84 km/h)95.87 mph (154.29 km/h)
95 mph (152.89 km/h)101.2 mph (162.86 km/h)
100 mph (160.93 km/h)106.52 mph (171.43 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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