Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
145/70r13 vs 145/90r13 Tire Comparison Side By Side
  145/70-13 145/90-13 Difference
Diameter inches (mm) 20.99 (533.2) 23.28 (591.2) 2.28 (58) 10.9%
Width inches (mm) 5.71 (145) 5.71 (145) 0 (0) 0%
Circum. inches (mm) 65.95 (1675.1) 73.12 (1857.31) 7.17 (182.21) 10.9%
Sidewall Height inches (mm) 4 (101.5) 5.14 (130.5) 1.14 (29) 28.6%
Revolutions per mile (km) 960.75 (596.98) 866.49 (538.41) -94.25 (-58.57) -9.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)22.18 mph (35.69 km/h)
25 mph (40.23 km/h)27.72 mph (44.61 km/h)
30 mph (48.28 km/h)33.26 mph (53.53 km/h)
35 mph (56.33 km/h)38.81 mph (62.45 km/h)
40 mph (64.37 km/h)44.35 mph (71.38 km/h)
45 mph (72.42 km/h)49.89 mph (80.3 km/h)
50 mph (80.47 km/h)55.44 mph (89.22 km/h)
55 mph (88.51 km/h)60.98 mph (98.14 km/h)
60 mph (96.56 km/h)66.53 mph (107.06 km/h)
65 mph (104.61 km/h)72.07 mph (115.99 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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