Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
175/55r15 vs 180/55r15 Tire Comparison Side By Side
  175/55-15 180/55-15 Difference
Diameter inches (mm) 22.58 (573.5) 22.8 (579) 0.22 (5.5) 1%
Width inches (mm) 6.89 (175) 7.09 (180) 0.2 (5) 2.9%
Circum. inches (mm) 70.93 (1801.7) 71.61 (1818.98) 0.68 (17.28) 1%
Sidewall Height inches (mm) 3.79 (96.25) 3.9 (99) 0.11 (2.75) 2.9%
Revolutions per mile (km) 893.23 (555.03) 884.75 (549.76) -8.48 (-5.27) -0.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.19 mph (32.5 km/h)
25 mph (40.23 km/h)25.24 mph (40.62 km/h)
30 mph (48.28 km/h)30.29 mph (48.74 km/h)
35 mph (56.33 km/h)35.34 mph (56.87 km/h)
40 mph (64.37 km/h)40.38 mph (64.99 km/h)
45 mph (72.42 km/h)45.43 mph (73.12 km/h)
50 mph (80.47 km/h)50.48 mph (81.24 km/h)
55 mph (88.51 km/h)55.53 mph (89.36 km/h)
60 mph (96.56 km/h)60.58 mph (97.49 km/h)
65 mph (104.61 km/h)65.62 mph (105.61 km/h)
70 mph (112.65 km/h)70.67 mph (113.73 km/h)
75 mph (120.7 km/h)75.72 mph (121.86 km/h)
80 mph (128.75 km/h)80.77 mph (129.98 km/h)
85 mph (136.79 km/h)85.82 mph (138.11 km/h)
90 mph (144.84 km/h)90.86 mph (146.23 km/h)
95 mph (152.89 km/h)95.91 mph (154.35 km/h)
100 mph (160.93 km/h)100.96 mph (162.48 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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