Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
175/70r12 vs 155/65r13 Tire Comparison Side By Side
  175/70-12 155/65-13 Difference
Diameter inches (mm) 21.65 (549.8) 20.93 (531.7) -0.71 (-18.1) -3.3%
Width inches (mm) 6.89 (175) 6.1 (155) -0.79 (-20) -11.4%
Circum. inches (mm) 68 (1727.25) 65.76 (1670.38) -2.24 (-56.86) -3.3%
Sidewall Height inches (mm) 4.82 (122.5) 3.97 (100.75) -0.86 (-21.75) -17.8%
Revolutions per mile (km) 931.74 (578.95) 963.46 (598.66) 31.72 (19.71) 3.4%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.34 mph (31.13 km/h)
25 mph (40.23 km/h)24.18 mph (38.91 km/h)
30 mph (48.28 km/h)29.01 mph (46.69 km/h)
35 mph (56.33 km/h)33.85 mph (54.47 km/h)
40 mph (64.37 km/h)38.68 mph (62.25 km/h)
45 mph (72.42 km/h)43.52 mph (70.04 km/h)
50 mph (80.47 km/h)48.35 mph (77.82 km/h)
55 mph (88.51 km/h)53.19 mph (85.6 km/h)
60 mph (96.56 km/h)58.02 mph (93.38 km/h)
65 mph (104.61 km/h)62.86 mph (101.16 km/h)
70 mph (112.65 km/h)67.7 mph (108.95 km/h)
75 mph (120.7 km/h)72.53 mph (116.73 km/h)
80 mph (128.75 km/h)77.37 mph (124.51 km/h)
85 mph (136.79 km/h)82.2 mph (132.29 km/h)
90 mph (144.84 km/h)87.04 mph (140.07 km/h)
95 mph (152.89 km/h)91.87 mph (147.85 km/h)
100 mph (160.93 km/h)96.71 mph (155.64 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
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
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