Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
275/55r18 vs 275/55r20 Tire Comparison Side By Side
  275/55-18 275/55-20 Difference
Diameter inches (mm) 29.91 (759.7) 31.91 (810.5) 2 (50.8) 6.7%
Width inches (mm) 10.83 (275) 10.83 (275) 0 (0) 0%
Circum. inches (mm) 93.96 (2386.67) 100.25 (2546.26) 6.28 (159.59) 6.7%
Sidewall Height inches (mm) 5.95 (151.25) 5.95 (151.25) 0 (0) 0%
Revolutions per mile (km) 674.31 (418.99) 632.04 (392.73) -42.26 (-26.26) -6.3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.34 mph (34.34 km/h)
25 mph (40.23 km/h)26.67 mph (42.92 km/h)
30 mph (48.28 km/h)32.01 mph (51.51 km/h)
35 mph (56.33 km/h)37.34 mph (60.09 km/h)
40 mph (64.37 km/h)42.67 mph (68.68 km/h)
45 mph (72.42 km/h)48.01 mph (77.26 km/h)
50 mph (80.47 km/h)53.34 mph (85.85 km/h)
55 mph (88.51 km/h)58.68 mph (94.43 km/h)
60 mph (96.56 km/h)64.01 mph (103.02 km/h)
65 mph (104.61 km/h)69.35 mph (111.6 km/h)
70 mph (112.65 km/h)74.68 mph (120.19 km/h)
75 mph (120.7 km/h)80.02 mph (128.77 km/h)
80 mph (128.75 km/h)85.35 mph (137.36 km/h)
85 mph (136.79 km/h)90.68 mph (145.94 km/h)
90 mph (144.84 km/h)96.02 mph (154.53 km/h)
95 mph (152.89 km/h)101.35 mph (163.11 km/h)
100 mph (160.93 km/h)106.69 mph (171.7 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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