Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
215/40r15 vs 205/50r15 Tire Comparison Side By Side
  215/40-15 205/50-15 Difference
Diameter inches (mm) 21.77 (553) 23.07 (586) 1.3 (33) 6%
Width inches (mm) 8.46 (215) 8.07 (205) -0.39 (-10) -4.7%
Circum. inches (mm) 68.4 (1737.3) 72.48 (1840.97) 4.08 (103.67) 6%
Sidewall Height inches (mm) 3.39 (86) 4.04 (102.5) 0.65 (16.5) 19.2%
Revolutions per mile (km) 926.35 (575.6) 874.18 (543.19) -52.17 (-32.41) -5.6%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.19 mph (34.11 km/h)
25 mph (40.23 km/h)26.49 mph (42.63 km/h)
30 mph (48.28 km/h)31.79 mph (51.16 km/h)
35 mph (56.33 km/h)37.09 mph (59.69 km/h)
40 mph (64.37 km/h)42.39 mph (68.22 km/h)
45 mph (72.42 km/h)47.69 mph (76.74 km/h)
50 mph (80.47 km/h)52.98 mph (85.27 km/h)
55 mph (88.51 km/h)58.28 mph (93.8 km/h)
60 mph (96.56 km/h)63.58 mph (102.32 km/h)
65 mph (104.61 km/h)68.88 mph (110.85 km/h)
70 mph (112.65 km/h)74.18 mph (119.38 km/h)
75 mph (120.7 km/h)79.48 mph (127.9 km/h)
80 mph (128.75 km/h)84.77 mph (136.43 km/h)
85 mph (136.79 km/h)90.07 mph (144.96 km/h)
90 mph (144.84 km/h)95.37 mph (153.48 km/h)
95 mph (152.89 km/h)100.67 mph (162.01 km/h)
100 mph (160.93 km/h)105.97 mph (170.54 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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