Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/50r17 vs 185/45r17 Tire Comparison Side By Side
  185/50-17 185/45-17 Difference
Diameter inches (mm) 24.28 (616.8) 23.56 (598.3) -0.73 (-18.5) -3%
Width inches (mm) 7.28 (185) 7.28 (185) 0 (0) 0%
Circum. inches (mm) 76.29 (1937.73) 74 (1879.61) -2.29 (-58.12) -3%
Sidewall Height inches (mm) 3.64 (92.5) 3.28 (83.25) -0.36 (-9.25) -10%
Revolutions per mile (km) 830.53 (516.07) 856.21 (532.02) 25.68 (15.96) 3.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.4 mph (31.22 km/h)
25 mph (40.23 km/h)24.25 mph (39.03 km/h)
30 mph (48.28 km/h)29.1 mph (46.83 km/h)
35 mph (56.33 km/h)33.95 mph (54.64 km/h)
40 mph (64.37 km/h)38.8 mph (62.44 km/h)
45 mph (72.42 km/h)43.65 mph (70.25 km/h)
50 mph (80.47 km/h)48.5 mph (78.05 km/h)
55 mph (88.51 km/h)53.35 mph (85.86 km/h)
60 mph (96.56 km/h)58.2 mph (93.66 km/h)
65 mph (104.61 km/h)63.05 mph (101.47 km/h)
70 mph (112.65 km/h)67.9 mph (109.28 km/h)
75 mph (120.7 km/h)72.75 mph (117.08 km/h)
80 mph (128.75 km/h)77.6 mph (124.89 km/h)
85 mph (136.79 km/h)82.45 mph (132.69 km/h)
90 mph (144.84 km/h)87.3 mph (140.5 km/h)
95 mph (152.89 km/h)92.15 mph (148.3 km/h)
100 mph (160.93 km/h)97 mph (156.11 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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