Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/55r15 vs 215/60r15 Tire Comparison Side By Side
  185/55-15 215/60-15 Difference
Diameter inches (mm) 23.01 (584.5) 25.16 (639) 2.15 (54.5) 9.3%
Width inches (mm) 7.28 (185) 8.46 (215) 1.18 (30) 16.2%
Circum. inches (mm) 72.29 (1836.26) 79.03 (2007.48) 6.74 (171.22) 9.3%
Sidewall Height inches (mm) 4.01 (101.75) 5.08 (129) 1.07 (27.25) 26.8%
Revolutions per mile (km) 876.42 (544.58) 801.67 (498.14) -74.75 (-46.45) -8.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.86 mph (35.19 km/h)
25 mph (40.23 km/h)27.33 mph (43.99 km/h)
30 mph (48.28 km/h)32.8 mph (52.78 km/h)
35 mph (56.33 km/h)38.26 mph (61.58 km/h)
40 mph (64.37 km/h)43.73 mph (70.38 km/h)
45 mph (72.42 km/h)49.2 mph (79.17 km/h)
50 mph (80.47 km/h)54.66 mph (87.97 km/h)
55 mph (88.51 km/h)60.13 mph (96.77 km/h)
60 mph (96.56 km/h)65.59 mph (105.56 km/h)
65 mph (104.61 km/h)71.06 mph (114.36 km/h)
70 mph (112.65 km/h)76.53 mph (123.16 km/h)
75 mph (120.7 km/h)81.99 mph (131.96 km/h)
80 mph (128.75 km/h)87.46 mph (140.75 km/h)
85 mph (136.79 km/h)92.93 mph (149.55 km/h)
90 mph (144.84 km/h)98.39 mph (158.35 km/h)
95 mph (152.89 km/h)103.86 mph (167.14 km/h)
100 mph (160.93 km/h)109.32 mph (175.94 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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