Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
100/80r12 vs 120/80r12 Tire Comparison Side By Side
  100/80-12 120/80-12 Difference
Diameter inches (mm) 18.3 (464.8) 19.56 (496.8) 1.26 (32) 6.9%
Width inches (mm) 3.94 (100) 4.72 (120) 0.79 (20) 20%
Circum. inches (mm) 57.49 (1460.21) 61.45 (1560.74) 3.96 (100.53) 6.9%
Sidewall Height inches (mm) 3.15 (80) 3.78 (96) 0.63 (16) 20%
Revolutions per mile (km) 1102.13 (684.83) 1031.14 (640.72) -70.99 (-44.11) -6.4%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.38 mph (34.4 km/h)
25 mph (40.23 km/h)26.72 mph (43 km/h)
30 mph (48.28 km/h)32.07 mph (51.6 km/h)
35 mph (56.33 km/h)37.41 mph (60.21 km/h)
40 mph (64.37 km/h)42.75 mph (68.81 km/h)
45 mph (72.42 km/h)48.1 mph (77.41 km/h)
50 mph (80.47 km/h)53.44 mph (86.01 km/h)
55 mph (88.51 km/h)58.79 mph (94.61 km/h)
60 mph (96.56 km/h)64.13 mph (103.21 km/h)
65 mph (104.61 km/h)69.48 mph (111.81 km/h)
70 mph (112.65 km/h)74.82 mph (120.41 km/h)
75 mph (120.7 km/h)80.16 mph (129.01 km/h)
80 mph (128.75 km/h)85.51 mph (137.61 km/h)
85 mph (136.79 km/h)90.85 mph (146.21 km/h)
90 mph (144.84 km/h)96.2 mph (154.81 km/h)
95 mph (152.89 km/h)101.54 mph (163.41 km/h)
100 mph (160.93 km/h)106.88 mph (172.01 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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