Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
115/70r15 vs 175/55r16 Tire Comparison Side By Side
  115/70-15 175/55-16 Difference
Diameter inches (mm) 21.34 (542) 23.58 (598.9) 2.24 (56.9) 10.5%
Width inches (mm) 4.53 (115) 6.89 (175) 2.36 (60) 52.2%
Circum. inches (mm) 67.04 (1702.74) 74.07 (1881.5) 7.04 (178.76) 10.5%
Sidewall Height inches (mm) 3.17 (80.5) 3.79 (96.25) 0.62 (15.75) 19.6%
Revolutions per mile (km) 945.15 (587.29) 855.35 (531.49) -89.8 (-55.8) -9.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)22.1 mph (35.57 km/h)
25 mph (40.23 km/h)27.62 mph (44.46 km/h)
30 mph (48.28 km/h)33.15 mph (53.35 km/h)
35 mph (56.33 km/h)38.67 mph (62.24 km/h)
40 mph (64.37 km/h)44.2 mph (71.13 km/h)
45 mph (72.42 km/h)49.72 mph (80.02 km/h)
50 mph (80.47 km/h)55.25 mph (88.91 km/h)
55 mph (88.51 km/h)60.77 mph (97.81 km/h)
60 mph (96.56 km/h)66.3 mph (106.7 km/h)
65 mph (104.61 km/h)71.82 mph (115.59 km/h)
70 mph (112.65 km/h)77.35 mph (124.48 km/h)
75 mph (120.7 km/h)82.87 mph (133.37 km/h)
80 mph (128.75 km/h)88.4 mph (142.26 km/h)
85 mph (136.79 km/h)93.92 mph (151.16 km/h)
90 mph (144.84 km/h)99.45 mph (160.05 km/h)
95 mph (152.89 km/h)104.97 mph (168.94 km/h)
100 mph (160.93 km/h)110.5 mph (177.83 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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