Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
255/35r21 vs 255/35r20 Tire Comparison Side By Side
  255/35-21 255/35-20 Difference
Diameter inches (mm) 28.03 (711.9) 27.03 (686.5) -1 (-25.4) -3.6%
Width inches (mm) 10.04 (255) 10.04 (255) 0 (0) 0%
Circum. inches (mm) 88.05 (2236.5) 84.91 (2156.7) -3.14 (-79.8) -3.6%
Sidewall Height inches (mm) 3.51 (89.25) 3.51 (89.25) 0 (0) 0%
Revolutions per mile (km) 719.58 (447.13) 746.21 (463.67) 26.62 (16.54) 3.7%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.29 mph (31.04 km/h)
25 mph (40.23 km/h)24.11 mph (38.8 km/h)
30 mph (48.28 km/h)28.93 mph (46.56 km/h)
35 mph (56.33 km/h)33.75 mph (54.32 km/h)
40 mph (64.37 km/h)38.57 mph (62.08 km/h)
45 mph (72.42 km/h)43.39 mph (69.84 km/h)
50 mph (80.47 km/h)48.22 mph (77.6 km/h)
55 mph (88.51 km/h)53.04 mph (85.36 km/h)
60 mph (96.56 km/h)57.86 mph (93.12 km/h)
65 mph (104.61 km/h)62.68 mph (100.88 km/h)
70 mph (112.65 km/h)67.5 mph (108.63 km/h)
75 mph (120.7 km/h)72.32 mph (116.39 km/h)
80 mph (128.75 km/h)77.15 mph (124.15 km/h)
85 mph (136.79 km/h)81.97 mph (131.91 km/h)
90 mph (144.84 km/h)86.79 mph (139.67 km/h)
95 mph (152.89 km/h)91.61 mph (147.43 km/h)
100 mph (160.93 km/h)96.43 mph (155.19 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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