Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
125/70r18 vs 225/45r17 Tire Comparison Side By Side
  125/70-18 225/45-17 Difference
Diameter inches (mm) 24.89 (632.2) 24.97 (634.3) 0.08 (2.1) 0.3%
Width inches (mm) 4.92 (125) 8.86 (225) 3.94 (100) 80%
Circum. inches (mm) 78.19 (1986.11) 78.45 (1992.71) 0.26 (6.6) 0.3%
Sidewall Height inches (mm) 3.44 (87.5) 3.99 (101.25) 0.54 (13.75) 15.7%
Revolutions per mile (km) 810.3 (503.49) 807.61 (501.83) -2.68 (-1.67) -0.3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.07 mph (32.29 km/h)
25 mph (40.23 km/h)25.08 mph (40.37 km/h)
30 mph (48.28 km/h)30.1 mph (48.44 km/h)
35 mph (56.33 km/h)35.12 mph (56.51 km/h)
40 mph (64.37 km/h)40.13 mph (64.59 km/h)
45 mph (72.42 km/h)45.15 mph (72.66 km/h)
50 mph (80.47 km/h)50.17 mph (80.73 km/h)
55 mph (88.51 km/h)55.18 mph (88.81 km/h)
60 mph (96.56 km/h)60.2 mph (96.88 km/h)
65 mph (104.61 km/h)65.22 mph (104.96 km/h)
70 mph (112.65 km/h)70.23 mph (113.03 km/h)
75 mph (120.7 km/h)75.25 mph (121.1 km/h)
80 mph (128.75 km/h)80.27 mph (129.18 km/h)
85 mph (136.79 km/h)85.28 mph (137.25 km/h)
90 mph (144.84 km/h)90.3 mph (145.32 km/h)
95 mph (152.89 km/h)95.32 mph (153.4 km/h)
100 mph (160.93 km/h)100.33 mph (161.47 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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