Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/70r13 vs 185/55r15 Tire Comparison Side By Side
  185/70-13 185/55-15 Difference
Diameter inches (mm) 23.2 (589.2) 23.01 (584.5) -0.19 (-4.7) -0.8%
Width inches (mm) 7.28 (185) 7.28 (185) 0 (0) 0%
Circum. inches (mm) 72.88 (1851.03) 72.29 (1836.26) -0.58 (-14.77) -0.8%
Sidewall Height inches (mm) 5.1 (129.5) 4.01 (101.75) -1.09 (-27.75) -21.4%
Revolutions per mile (km) 869.43 (540.24) 876.42 (544.58) 6.99 (4.34) 0.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.84 mph (31.93 km/h)
25 mph (40.23 km/h)24.8 mph (39.91 km/h)
30 mph (48.28 km/h)29.76 mph (47.9 km/h)
35 mph (56.33 km/h)34.72 mph (55.88 km/h)
40 mph (64.37 km/h)39.68 mph (63.86 km/h)
45 mph (72.42 km/h)44.64 mph (71.84 km/h)
50 mph (80.47 km/h)49.6 mph (79.83 km/h)
55 mph (88.51 km/h)54.56 mph (87.81 km/h)
60 mph (96.56 km/h)59.52 mph (95.79 km/h)
65 mph (104.61 km/h)64.48 mph (103.77 km/h)
70 mph (112.65 km/h)69.44 mph (111.76 km/h)
75 mph (120.7 km/h)74.4 mph (119.74 km/h)
80 mph (128.75 km/h)79.36 mph (127.72 km/h)
85 mph (136.79 km/h)84.32 mph (135.7 km/h)
90 mph (144.84 km/h)89.28 mph (143.69 km/h)
95 mph (152.89 km/h)94.24 mph (151.67 km/h)
100 mph (160.93 km/h)99.2 mph (159.65 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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