Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
265/40r21 vs 245/55r19 Tire Comparison Side By Side
  265/40-21 245/55-19 Difference
Diameter inches (mm) 29.35 (745.4) 29.61 (752.1) 0.26 (6.7) 0.9%
Width inches (mm) 10.43 (265) 9.65 (245) -0.79 (-20) -7.5%
Circum. inches (mm) 92.19 (2341.74) 93.02 (2362.79) 0.83 (21.05) 0.9%
Sidewall Height inches (mm) 4.17 (106) 5.31 (134.75) 1.13 (28.75) 27.1%
Revolutions per mile (km) 687.24 (427.03) 681.12 (423.23) -6.12 (-3.8) -0.9%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.18 mph (32.48 km/h)
25 mph (40.23 km/h)25.22 mph (40.6 km/h)
30 mph (48.28 km/h)30.27 mph (48.71 km/h)
35 mph (56.33 km/h)35.31 mph (56.83 km/h)
40 mph (64.37 km/h)40.36 mph (64.95 km/h)
45 mph (72.42 km/h)45.4 mph (73.07 km/h)
50 mph (80.47 km/h)50.45 mph (81.19 km/h)
55 mph (88.51 km/h)55.49 mph (89.31 km/h)
60 mph (96.56 km/h)60.54 mph (97.43 km/h)
65 mph (104.61 km/h)65.58 mph (105.55 km/h)
70 mph (112.65 km/h)70.63 mph (113.67 km/h)
75 mph (120.7 km/h)75.67 mph (121.79 km/h)
80 mph (128.75 km/h)80.72 mph (129.91 km/h)
85 mph (136.79 km/h)85.76 mph (138.02 km/h)
90 mph (144.84 km/h)90.81 mph (146.14 km/h)
95 mph (152.89 km/h)95.85 mph (154.26 km/h)
100 mph (160.93 km/h)100.9 mph (162.38 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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