Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
225/40r18 vs 225/50r17 Tire Comparison Side By Side
  225/40-18 225/50-17 Difference
Diameter inches (mm) 25.09 (637.2) 25.86 (656.8) 0.77 (19.6) 3.1%
Width inches (mm) 8.86 (225) 8.86 (225) 0 (0) 0%
Circum. inches (mm) 78.81 (2001.82) 81.24 (2063.4) 2.42 (61.58) 3.1%
Sidewall Height inches (mm) 3.54 (90) 4.43 (112.5) 0.89 (22.5) 25%
Revolutions per mile (km) 803.94 (499.54) 779.95 (484.64) -23.99 (-14.91) -3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.62 mph (33.18 km/h)
25 mph (40.23 km/h)25.77 mph (41.47 km/h)
30 mph (48.28 km/h)30.92 mph (49.77 km/h)
35 mph (56.33 km/h)36.08 mph (58.06 km/h)
40 mph (64.37 km/h)41.23 mph (66.35 km/h)
45 mph (72.42 km/h)46.38 mph (74.65 km/h)
50 mph (80.47 km/h)51.54 mph (82.94 km/h)
55 mph (88.51 km/h)56.69 mph (91.24 km/h)
60 mph (96.56 km/h)61.85 mph (99.53 km/h)
65 mph (104.61 km/h)67 mph (107.83 km/h)
70 mph (112.65 km/h)72.15 mph (116.12 km/h)
75 mph (120.7 km/h)77.31 mph (124.41 km/h)
80 mph (128.75 km/h)82.46 mph (132.71 km/h)
85 mph (136.79 km/h)87.61 mph (141 km/h)
90 mph (144.84 km/h)92.77 mph (149.3 km/h)
95 mph (152.89 km/h)97.92 mph (157.59 km/h)
100 mph (160.93 km/h)103.08 mph (165.88 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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