Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
100/70r12 vs 120/70r12 Tire Comparison Side By Side
  100/70-12 120/70-12 Difference
Diameter inches (mm) 17.51 (444.8) 18.61 (472.8) 1.1 (28) 6.3%
Width inches (mm) 3.94 (100) 4.72 (120) 0.79 (20) 20%
Circum. inches (mm) 55.01 (1397.38) 58.48 (1485.35) 3.46 (87.96) 6.3%
Sidewall Height inches (mm) 2.76 (70) 3.31 (84) 0.55 (14) 20%
Revolutions per mile (km) 1151.69 (715.62) 1083.48 (673.24) -68.2 (-42.38) -5.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.26 mph (34.21 km/h)
25 mph (40.23 km/h)26.57 mph (42.77 km/h)
30 mph (48.28 km/h)31.89 mph (51.32 km/h)
35 mph (56.33 km/h)37.2 mph (59.87 km/h)
40 mph (64.37 km/h)42.52 mph (68.43 km/h)
45 mph (72.42 km/h)47.83 mph (76.98 km/h)
50 mph (80.47 km/h)53.15 mph (85.53 km/h)
55 mph (88.51 km/h)58.46 mph (94.09 km/h)
60 mph (96.56 km/h)63.78 mph (102.64 km/h)
65 mph (104.61 km/h)69.09 mph (111.19 km/h)
70 mph (112.65 km/h)74.41 mph (119.75 km/h)
75 mph (120.7 km/h)79.72 mph (128.3 km/h)
80 mph (128.75 km/h)85.04 mph (136.85 km/h)
85 mph (136.79 km/h)90.35 mph (145.41 km/h)
90 mph (144.84 km/h)95.67 mph (153.96 km/h)
95 mph (152.89 km/h)100.98 mph (162.51 km/h)
100 mph (160.93 km/h)106.29 mph (171.07 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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