Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
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125/70r14 vs 170/40r14 Tire Comparison Side By Side
  125/70-14 170/40-14 Difference
Diameter inches (mm) 20.89 (530.6) 19.35 (491.6) -1.54 (-39) -7.4%
Width inches (mm) 4.92 (125) 6.69 (170) 1.77 (45) 36%
Circum. inches (mm) 65.63 (1666.93) 60.8 (1544.41) -4.82 (-122.52) -7.4%
Sidewall Height inches (mm) 3.44 (87.5) 2.68 (68) -0.77 (-19.5) -22.3%
Revolutions per mile (km) 965.45 (599.9) 1042.05 (647.5) 76.59 (47.59) 7.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)18.53 mph (29.82 km/h)
25 mph (40.23 km/h)23.16 mph (37.28 km/h)
30 mph (48.28 km/h)27.79 mph (44.73 km/h)
35 mph (56.33 km/h)32.43 mph (52.19 km/h)
40 mph (64.37 km/h)37.06 mph (59.64 km/h)
45 mph (72.42 km/h)41.69 mph (67.1 km/h)
50 mph (80.47 km/h)46.32 mph (74.55 km/h)
55 mph (88.51 km/h)50.96 mph (82.01 km/h)
60 mph (96.56 km/h)55.59 mph (89.46 km/h)
65 mph (104.61 km/h)60.22 mph (96.92 km/h)
70 mph (112.65 km/h)64.85 mph (104.37 km/h)
75 mph (120.7 km/h)69.49 mph (111.83 km/h)
80 mph (128.75 km/h)74.12 mph (119.28 km/h)
85 mph (136.79 km/h)78.75 mph (126.74 km/h)
90 mph (144.84 km/h)83.38 mph (134.2 km/h)
95 mph (152.89 km/h)88.02 mph (141.65 km/h)
100 mph (160.93 km/h)92.65 mph (149.11 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
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
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