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 125/65r15 Tire Comparison Side By Side
  125/70-15 125/65-15 Difference
Diameter inches (mm) 21.89 (556) 21.4 (543.5) -0.49 (-12.5) -2.2%
Width inches (mm) 4.92 (125) 4.92 (125) 0 (0) 0%
Circum. inches (mm) 68.77 (1746.73) 67.22 (1707.46) -1.55 (-39.27) -2.2%
Sidewall Height inches (mm) 3.44 (87.5) 3.2 (81.25) -0.25 (-6.25) -7.1%
Revolutions per mile (km) 921.35 (572.5) 942.54 (585.67) 21.19 (13.17) 2.3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.55 mph (31.46 km/h)
25 mph (40.23 km/h)24.44 mph (39.33 km/h)
30 mph (48.28 km/h)29.33 mph (47.19 km/h)
35 mph (56.33 km/h)34.21 mph (55.06 km/h)
40 mph (64.37 km/h)39.1 mph (62.93 km/h)
45 mph (72.42 km/h)43.99 mph (70.79 km/h)
50 mph (80.47 km/h)48.88 mph (78.66 km/h)
55 mph (88.51 km/h)53.76 mph (86.52 km/h)
60 mph (96.56 km/h)58.65 mph (94.39 km/h)
65 mph (104.61 km/h)63.54 mph (102.26 km/h)
70 mph (112.65 km/h)68.43 mph (110.12 km/h)
75 mph (120.7 km/h)73.31 mph (117.99 km/h)
80 mph (128.75 km/h)78.2 mph (125.85 km/h)
85 mph (136.79 km/h)83.09 mph (133.72 km/h)
90 mph (144.84 km/h)87.98 mph (141.58 km/h)
95 mph (152.89 km/h)92.86 mph (149.45 km/h)
100 mph (160.93 km/h)97.75 mph (157.32 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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