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 265/40r20 Tire Comparison Side By Side
  265/35-21 265/40-20 Difference
Diameter inches (mm) 28.3 (718.9) 28.35 (720) 0.04 (1.1) 0.2%
Width inches (mm) 10.43 (265) 10.43 (265) 0 (0) 0%
Circum. inches (mm) 88.92 (2258.49) 89.05 (2261.95) 0.14 (3.46) 0.2%
Sidewall Height inches (mm) 3.65 (92.75) 4.17 (106) 0.52 (13.25) 14.3%
Revolutions per mile (km) 712.57 (442.77) 711.49 (442.1) -1.09 (-0.68) -0.2%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.03 mph (32.24 km/h)
25 mph (40.23 km/h)25.04 mph (40.3 km/h)
30 mph (48.28 km/h)30.05 mph (48.35 km/h)
35 mph (56.33 km/h)35.05 mph (56.41 km/h)
40 mph (64.37 km/h)40.06 mph (64.47 km/h)
45 mph (72.42 km/h)45.07 mph (72.53 km/h)
50 mph (80.47 km/h)50.08 mph (80.59 km/h)
55 mph (88.51 km/h)55.08 mph (88.65 km/h)
60 mph (96.56 km/h)60.09 mph (96.71 km/h)
65 mph (104.61 km/h)65.1 mph (104.77 km/h)
70 mph (112.65 km/h)70.11 mph (112.83 km/h)
75 mph (120.7 km/h)75.11 mph (120.89 km/h)
80 mph (128.75 km/h)80.12 mph (128.94 km/h)
85 mph (136.79 km/h)85.13 mph (137 km/h)
90 mph (144.84 km/h)90.14 mph (145.06 km/h)
95 mph (152.89 km/h)95.15 mph (153.12 km/h)
100 mph (160.93 km/h)100.15 mph (161.18 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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