Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
265/35r21 vs 285/35r20 Tire Comparison Side By Side
  265/35-21 285/35-20 Difference
Diameter inches (mm) 28.3 (718.9) 27.85 (707.5) -0.45 (-11.4) -1.6%
Width inches (mm) 10.43 (265) 11.22 (285) 0.79 (20) 7.5%
Circum. inches (mm) 88.92 (2258.49) 87.51 (2222.68) -1.41 (-35.81) -1.6%
Sidewall Height inches (mm) 3.65 (92.75) 3.93 (99.75) 0.28 (7) 7.5%
Revolutions per mile (km) 712.57 (442.77) 724.06 (449.91) 11.48 (7.13) 1.6%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.68 mph (31.68 km/h)
25 mph (40.23 km/h)24.6 mph (39.6 km/h)
30 mph (48.28 km/h)29.52 mph (47.51 km/h)
35 mph (56.33 km/h)34.44 mph (55.43 km/h)
40 mph (64.37 km/h)39.37 mph (63.35 km/h)
45 mph (72.42 km/h)44.29 mph (71.27 km/h)
50 mph (80.47 km/h)49.21 mph (79.19 km/h)
55 mph (88.51 km/h)54.13 mph (87.11 km/h)
60 mph (96.56 km/h)59.05 mph (95.03 km/h)
65 mph (104.61 km/h)63.97 mph (102.95 km/h)
70 mph (112.65 km/h)68.89 mph (110.87 km/h)
75 mph (120.7 km/h)73.81 mph (118.79 km/h)
80 mph (128.75 km/h)78.73 mph (126.71 km/h)
85 mph (136.79 km/h)83.65 mph (134.63 km/h)
90 mph (144.84 km/h)88.57 mph (142.54 km/h)
95 mph (152.89 km/h)93.49 mph (150.46 km/h)
100 mph (160.93 km/h)98.41 mph (158.38 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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