Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
120/100r18 vs 140/90r18 Tire Comparison Side By Side
  120/100-18 140/90-18 Difference
Diameter inches (mm) 27.45 (697.2) 27.92 (709.2) 0.47 (12) 1.7%
Width inches (mm) 4.72 (120) 5.51 (140) 0.79 (20) 16.7%
Circum. inches (mm) 86.23 (2190.32) 87.72 (2228.02) 1.48 (37.7) 1.7%
Sidewall Height inches (mm) 4.72 (120) 4.96 (126) 0.24 (6) 5%
Revolutions per mile (km) 734.75 (456.55) 722.32 (448.83) -12.43 (-7.73) -1.7%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.34 mph (32.74 km/h)
25 mph (40.23 km/h)25.43 mph (40.93 km/h)
30 mph (48.28 km/h)30.52 mph (49.11 km/h)
35 mph (56.33 km/h)35.6 mph (57.3 km/h)
40 mph (64.37 km/h)40.69 mph (65.48 km/h)
45 mph (72.42 km/h)45.77 mph (73.67 km/h)
50 mph (80.47 km/h)50.86 mph (81.85 km/h)
55 mph (88.51 km/h)55.95 mph (90.04 km/h)
60 mph (96.56 km/h)61.03 mph (98.22 km/h)
65 mph (104.61 km/h)66.12 mph (106.41 km/h)
70 mph (112.65 km/h)71.2 mph (114.59 km/h)
75 mph (120.7 km/h)76.29 mph (122.78 km/h)
80 mph (128.75 km/h)81.38 mph (130.96 km/h)
85 mph (136.79 km/h)86.46 mph (139.15 km/h)
90 mph (144.84 km/h)91.55 mph (147.33 km/h)
95 mph (152.89 km/h)96.64 mph (155.52 km/h)
100 mph (160.93 km/h)101.72 mph (163.7 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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