Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
285/35r21 vs 275/35r21 Tire Comparison Side By Side
  285/35-21 275/35-21 Difference
Diameter inches (mm) 28.85 (732.9) 28.58 (725.9) -0.28 (-7) -1%
Width inches (mm) 11.22 (285) 10.83 (275) -0.39 (-10) -3.5%
Circum. inches (mm) 90.65 (2302.47) 89.78 (2280.48) -0.87 (-21.99) -1%
Sidewall Height inches (mm) 3.93 (99.75) 3.79 (96.25) -0.14 (-3.5) -3.5%
Revolutions per mile (km) 698.96 (434.31) 705.7 (438.5) 6.74 (4.19) 1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.81 mph (31.88 km/h)
25 mph (40.23 km/h)24.76 mph (39.85 km/h)
30 mph (48.28 km/h)29.71 mph (47.82 km/h)
35 mph (56.33 km/h)34.67 mph (55.79 km/h)
40 mph (64.37 km/h)39.62 mph (63.76 km/h)
45 mph (72.42 km/h)44.57 mph (71.73 km/h)
50 mph (80.47 km/h)49.52 mph (79.7 km/h)
55 mph (88.51 km/h)54.47 mph (87.67 km/h)
60 mph (96.56 km/h)59.43 mph (95.64 km/h)
65 mph (104.61 km/h)64.38 mph (103.61 km/h)
70 mph (112.65 km/h)69.33 mph (111.58 km/h)
75 mph (120.7 km/h)74.28 mph (119.55 km/h)
80 mph (128.75 km/h)79.24 mph (127.52 km/h)
85 mph (136.79 km/h)84.19 mph (135.49 km/h)
90 mph (144.84 km/h)89.14 mph (143.46 km/h)
95 mph (152.89 km/h)94.09 mph (151.43 km/h)
100 mph (160.93 km/h)99.04 mph (159.4 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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