Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
180/70r15 vs 195/65r15 Tire Comparison Side By Side
  180/70-15 195/65-15 Difference
Diameter inches (mm) 24.92 (633) 24.98 (634.5) 0.06 (1.5) 0.2%
Width inches (mm) 7.09 (180) 7.68 (195) 0.59 (15) 8.3%
Circum. inches (mm) 78.29 (1988.63) 78.48 (1993.34) 0.19 (4.71) 0.2%
Sidewall Height inches (mm) 4.96 (126) 4.99 (126.75) 0.03 (0.75) 0.6%
Revolutions per mile (km) 809.27 (502.86) 807.36 (501.67) -1.91 (-1.19) -0.2%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.05 mph (32.26 km/h)
25 mph (40.23 km/h)25.06 mph (40.33 km/h)
30 mph (48.28 km/h)30.07 mph (48.39 km/h)
35 mph (56.33 km/h)35.08 mph (56.46 km/h)
40 mph (64.37 km/h)40.09 mph (64.53 km/h)
45 mph (72.42 km/h)45.11 mph (72.59 km/h)
50 mph (80.47 km/h)50.12 mph (80.66 km/h)
55 mph (88.51 km/h)55.13 mph (88.72 km/h)
60 mph (96.56 km/h)60.14 mph (96.79 km/h)
65 mph (104.61 km/h)65.15 mph (104.86 km/h)
70 mph (112.65 km/h)70.17 mph (112.92 km/h)
75 mph (120.7 km/h)75.18 mph (120.99 km/h)
80 mph (128.75 km/h)80.19 mph (129.05 km/h)
85 mph (136.79 km/h)85.2 mph (137.12 km/h)
90 mph (144.84 km/h)90.21 mph (145.18 km/h)
95 mph (152.89 km/h)95.23 mph (153.25 km/h)
100 mph (160.93 km/h)100.24 mph (161.32 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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