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 205/50r15 Tire Comparison Side By Side
  185/50-15 205/50-15 Difference
Diameter inches (mm) 22.28 (566) 23.07 (586) 0.79 (20) 3.5%
Width inches (mm) 7.28 (185) 8.07 (205) 0.79 (20) 10.8%
Circum. inches (mm) 70.01 (1778.14) 72.48 (1840.97) 2.47 (62.83) 3.5%
Sidewall Height inches (mm) 3.64 (92.5) 4.04 (102.5) 0.39 (10) 10.8%
Revolutions per mile (km) 905.07 (562.38) 874.18 (543.19) -30.89 (-19.19) -3.4%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.71 mph (33.32 km/h)
25 mph (40.23 km/h)25.88 mph (41.66 km/h)
30 mph (48.28 km/h)31.06 mph (49.99 km/h)
35 mph (56.33 km/h)36.24 mph (58.32 km/h)
40 mph (64.37 km/h)41.41 mph (66.65 km/h)
45 mph (72.42 km/h)46.59 mph (74.98 km/h)
50 mph (80.47 km/h)51.77 mph (83.31 km/h)
55 mph (88.51 km/h)56.94 mph (91.64 km/h)
60 mph (96.56 km/h)62.12 mph (99.97 km/h)
65 mph (104.61 km/h)67.3 mph (108.3 km/h)
70 mph (112.65 km/h)72.47 mph (116.64 km/h)
75 mph (120.7 km/h)77.65 mph (124.97 km/h)
80 mph (128.75 km/h)82.83 mph (133.3 km/h)
85 mph (136.79 km/h)88 mph (141.63 km/h)
90 mph (144.84 km/h)93.18 mph (149.96 km/h)
95 mph (152.89 km/h)98.36 mph (158.29 km/h)
100 mph (160.93 km/h)103.53 mph (166.62 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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