Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
125/70r17 vs 225/45r18 Tire Comparison Side By Side
  125/70-17 225/45-18 Difference
Diameter inches (mm) 23.89 (606.8) 25.97 (659.7) 2.08 (52.9) 8.7%
Width inches (mm) 4.92 (125) 8.86 (225) 3.94 (100) 80%
Circum. inches (mm) 75.05 (1906.32) 81.59 (2072.51) 6.54 (166.19) 8.7%
Sidewall Height inches (mm) 3.44 (87.5) 3.99 (101.25) 0.54 (13.75) 15.7%
Revolutions per mile (km) 844.22 (524.57) 776.52 (482.51) -67.7 (-42.06) -8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.74 mph (34.99 km/h)
25 mph (40.23 km/h)27.18 mph (43.74 km/h)
30 mph (48.28 km/h)32.62 mph (52.49 km/h)
35 mph (56.33 km/h)38.05 mph (61.24 km/h)
40 mph (64.37 km/h)43.49 mph (69.99 km/h)
45 mph (72.42 km/h)48.92 mph (78.73 km/h)
50 mph (80.47 km/h)54.36 mph (87.48 km/h)
55 mph (88.51 km/h)59.79 mph (96.23 km/h)
60 mph (96.56 km/h)65.23 mph (104.98 km/h)
65 mph (104.61 km/h)70.67 mph (113.73 km/h)
70 mph (112.65 km/h)76.1 mph (122.48 km/h)
75 mph (120.7 km/h)81.54 mph (131.22 km/h)
80 mph (128.75 km/h)86.97 mph (139.97 km/h)
85 mph (136.79 km/h)92.41 mph (148.72 km/h)
90 mph (144.84 km/h)97.85 mph (157.47 km/h)
95 mph (152.89 km/h)103.28 mph (166.22 km/h)
100 mph (160.93 km/h)108.72 mph (174.96 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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