Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
125/70r15 vs 175/80r14 Tire Comparison Side By Side
  125/70-15 175/80-14 Difference
Diameter inches (mm) 21.89 (556) 25.02 (635.6) 3.13 (79.6) 14.3%
Width inches (mm) 4.92 (125) 6.89 (175) 1.97 (50) 40%
Circum. inches (mm) 68.77 (1746.73) 78.61 (1996.8) 9.85 (250.07) 14.3%
Sidewall Height inches (mm) 3.44 (87.5) 5.51 (140) 2.07 (52.5) 60%
Revolutions per mile (km) 921.35 (572.5) 805.96 (500.8) -115.39 (-71.7) -12.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)22.86 mph (36.8 km/h)
25 mph (40.23 km/h)28.58 mph (45.99 km/h)
30 mph (48.28 km/h)34.29 mph (55.19 km/h)
35 mph (56.33 km/h)40.01 mph (64.39 km/h)
40 mph (64.37 km/h)45.73 mph (73.59 km/h)
45 mph (72.42 km/h)51.44 mph (82.79 km/h)
50 mph (80.47 km/h)57.16 mph (91.99 km/h)
55 mph (88.51 km/h)62.87 mph (101.19 km/h)
60 mph (96.56 km/h)68.59 mph (110.39 km/h)
65 mph (104.61 km/h)74.31 mph (119.58 km/h)
70 mph (112.65 km/h)80.02 mph (128.78 km/h)
75 mph (120.7 km/h)85.74 mph (137.98 km/h)
80 mph (128.75 km/h)91.45 mph (147.18 km/h)
85 mph (136.79 km/h)97.17 mph (156.38 km/h)
90 mph (144.84 km/h)102.88 mph (165.58 km/h)
95 mph (152.89 km/h)108.6 mph (174.78 km/h)
100 mph (160.93 km/h)114.32 mph (183.98 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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