Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/50r15 vs 185/55r15 Tire Comparison Side By Side
  185/50-15 185/55-15 Difference
Diameter inches (mm) 22.28 (566) 23.01 (584.5) 0.73 (18.5) 3.3%
Width inches (mm) 7.28 (185) 7.28 (185) 0 (0) 0%
Circum. inches (mm) 70.01 (1778.14) 72.29 (1836.26) 2.29 (58.12) 3.3%
Sidewall Height inches (mm) 3.64 (92.5) 4.01 (101.75) 0.36 (9.25) 10%
Revolutions per mile (km) 905.07 (562.38) 876.42 (544.58) -28.65 (-17.8) -3.2%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.65 mph (33.24 km/h)
25 mph (40.23 km/h)25.82 mph (41.55 km/h)
30 mph (48.28 km/h)30.98 mph (49.86 km/h)
35 mph (56.33 km/h)36.14 mph (58.17 km/h)
40 mph (64.37 km/h)41.31 mph (66.48 km/h)
45 mph (72.42 km/h)46.47 mph (74.79 km/h)
50 mph (80.47 km/h)51.63 mph (83.1 km/h)
55 mph (88.51 km/h)56.8 mph (91.41 km/h)
60 mph (96.56 km/h)61.96 mph (99.72 km/h)
65 mph (104.61 km/h)67.12 mph (108.03 km/h)
70 mph (112.65 km/h)72.29 mph (116.34 km/h)
75 mph (120.7 km/h)77.45 mph (124.65 km/h)
80 mph (128.75 km/h)82.61 mph (132.96 km/h)
85 mph (136.79 km/h)87.78 mph (141.27 km/h)
90 mph (144.84 km/h)92.94 mph (149.58 km/h)
95 mph (152.89 km/h)98.11 mph (157.89 km/h)
100 mph (160.93 km/h)103.27 mph (166.19 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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