Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/65r15 vs 185/70r14 Tire Comparison Side By Side
  185/65-15 185/70-14 Difference
Diameter inches (mm) 24.47 (621.5) 24.2 (614.6) -0.27 (-6.9) -1.1%
Width inches (mm) 7.28 (185) 7.28 (185) 0 (0) 0%
Circum. inches (mm) 76.87 (1952.5) 76.02 (1930.82) -0.85 (-21.68) -1.1%
Sidewall Height inches (mm) 4.73 (120.25) 5.1 (129.5) 0.36 (9.25) 7.7%
Revolutions per mile (km) 824.25 (512.16) 833.5 (517.91) 9.25 (5.75) 1.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.78 mph (31.83 km/h)
25 mph (40.23 km/h)24.72 mph (39.79 km/h)
30 mph (48.28 km/h)29.67 mph (47.74 km/h)
35 mph (56.33 km/h)34.61 mph (55.7 km/h)
40 mph (64.37 km/h)39.56 mph (63.66 km/h)
45 mph (72.42 km/h)44.5 mph (71.62 km/h)
50 mph (80.47 km/h)49.44 mph (79.57 km/h)
55 mph (88.51 km/h)54.39 mph (87.53 km/h)
60 mph (96.56 km/h)59.33 mph (95.49 km/h)
65 mph (104.61 km/h)64.28 mph (103.45 km/h)
70 mph (112.65 km/h)69.22 mph (111.4 km/h)
75 mph (120.7 km/h)74.17 mph (119.36 km/h)
80 mph (128.75 km/h)79.11 mph (127.32 km/h)
85 mph (136.79 km/h)84.06 mph (135.28 km/h)
90 mph (144.84 km/h)89 mph (143.23 km/h)
95 mph (152.89 km/h)93.95 mph (151.19 km/h)
100 mph (160.93 km/h)98.89 mph (159.15 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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