Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
225/45r21 vs 225/35r19 Tire Comparison Side By Side
  225/45-21 225/35-19 Difference
Diameter inches (mm) 28.97 (735.9) 25.2 (640.1) -3.77 (-95.8) -13%
Width inches (mm) 8.86 (225) 8.86 (225) 0 (0) 0%
Circum. inches (mm) 91.02 (2311.9) 79.17 (2010.93) -11.85 (-300.96) -13%
Sidewall Height inches (mm) 3.99 (101.25) 3.1 (78.75) -0.89 (-22.5) -22.2%
Revolutions per mile (km) 696.11 (432.54) 800.3 (497.28) 104.18 (64.74) 15%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)17.4 mph (28 km/h)
25 mph (40.23 km/h)21.75 mph (35 km/h)
30 mph (48.28 km/h)26.09 mph (42 km/h)
35 mph (56.33 km/h)30.44 mph (48.99 km/h)
40 mph (64.37 km/h)34.79 mph (55.99 km/h)
45 mph (72.42 km/h)39.14 mph (62.99 km/h)
50 mph (80.47 km/h)43.49 mph (69.99 km/h)
55 mph (88.51 km/h)47.84 mph (76.99 km/h)
60 mph (96.56 km/h)52.19 mph (83.99 km/h)
65 mph (104.61 km/h)56.54 mph (90.99 km/h)
70 mph (112.65 km/h)60.89 mph (97.99 km/h)
75 mph (120.7 km/h)65.24 mph (104.99 km/h)
80 mph (128.75 km/h)69.59 mph (111.99 km/h)
85 mph (136.79 km/h)73.93 mph (118.99 km/h)
90 mph (144.84 km/h)78.28 mph (125.99 km/h)
95 mph (152.89 km/h)82.63 mph (132.98 km/h)
100 mph (160.93 km/h)86.98 mph (139.98 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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