Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
30/9.5r15 vs 265/75r15 Tire Comparison Side By Side
  30/9.5-15 265/75-15 Difference
Diameter inches (mm) 29.99 (761.78) 30.65 (778.5) 0.66 (16.72) 2.2%
Width inches (mm) 9.49 (241) 10.43 (265) 0.94 (24) 10%
Circum. inches (mm) 94.22 (2393.2) 96.29 (2445.73) 2.07 (52.53) 2.2%
Sidewall Height inches (mm) 7.5 (190.39) 7.82 (198.75) 0.33 (8.36) 4.4%
Revolutions per mile (km) 672.46 (417.85) 658.02 (408.88) -14.44 (-8.97) -2.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.44 mph (32.89 km/h)
25 mph (40.23 km/h)25.55 mph (41.12 km/h)
30 mph (48.28 km/h)30.66 mph (49.34 km/h)
35 mph (56.33 km/h)35.77 mph (57.56 km/h)
40 mph (64.37 km/h)40.88 mph (65.79 km/h)
45 mph (72.42 km/h)45.99 mph (74.01 km/h)
50 mph (80.47 km/h)51.1 mph (82.23 km/h)
55 mph (88.51 km/h)56.21 mph (90.46 km/h)
60 mph (96.56 km/h)61.32 mph (98.68 km/h)
65 mph (104.61 km/h)66.43 mph (106.9 km/h)
70 mph (112.65 km/h)71.54 mph (115.13 km/h)
75 mph (120.7 km/h)76.65 mph (123.35 km/h)
80 mph (128.75 km/h)81.76 mph (131.57 km/h)
85 mph (136.79 km/h)86.87 mph (139.8 km/h)
90 mph (144.84 km/h)91.98 mph (148.02 km/h)
95 mph (152.89 km/h)97.09 mph (156.24 km/h)
100 mph (160.93 km/h)102.19 mph (164.47 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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