Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
245/35r21 vs 235/35r21 Tire Comparison Side By Side
  245/35-21 235/35-21 Difference
Diameter inches (mm) 27.75 (704.9) 27.48 (697.9) -0.28 (-7) -1%
Width inches (mm) 9.65 (245) 9.25 (235) -0.39 (-10) -4.1%
Circum. inches (mm) 87.19 (2214.51) 86.32 (2192.52) -0.87 (-21.99) -1%
Sidewall Height inches (mm) 3.38 (85.75) 3.24 (82.25) -0.14 (-3.5) -4.1%
Revolutions per mile (km) 726.73 (451.57) 734.02 (456.1) 7.29 (4.53) 1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.8 mph (31.87 km/h)
25 mph (40.23 km/h)24.75 mph (39.83 km/h)
30 mph (48.28 km/h)29.7 mph (47.8 km/h)
35 mph (56.33 km/h)34.65 mph (55.77 km/h)
40 mph (64.37 km/h)39.6 mph (63.73 km/h)
45 mph (72.42 km/h)44.55 mph (71.7 km/h)
50 mph (80.47 km/h)49.5 mph (79.67 km/h)
55 mph (88.51 km/h)54.45 mph (87.64 km/h)
60 mph (96.56 km/h)59.4 mph (95.6 km/h)
65 mph (104.61 km/h)64.35 mph (103.57 km/h)
70 mph (112.65 km/h)69.3 mph (111.54 km/h)
75 mph (120.7 km/h)74.26 mph (119.5 km/h)
80 mph (128.75 km/h)79.21 mph (127.47 km/h)
85 mph (136.79 km/h)84.16 mph (135.44 km/h)
90 mph (144.84 km/h)89.11 mph (143.4 km/h)
95 mph (152.89 km/h)94.06 mph (151.37 km/h)
100 mph (160.93 km/h)99.01 mph (159.34 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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