Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
215/40r12 vs 215/35r14 Tire Comparison Side By Side
  215/40-12 215/35-14 Difference
Diameter inches (mm) 18.77 (476.8) 19.93 (506.1) 1.15 (29.3) 6.1%
Width inches (mm) 8.46 (215) 8.46 (215) 0 (0) 0%
Circum. inches (mm) 58.97 (1497.91) 62.6 (1589.96) 3.62 (92.05) 6.1%
Sidewall Height inches (mm) 3.39 (86) 2.96 (75.25) -0.42 (-10.75) -12.5%
Revolutions per mile (km) 1074.39 (667.59) 1012.19 (628.95) -62.2 (-38.65) -5.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.23 mph (34.16 km/h)
25 mph (40.23 km/h)26.54 mph (42.71 km/h)
30 mph (48.28 km/h)31.84 mph (51.25 km/h)
35 mph (56.33 km/h)37.15 mph (59.79 km/h)
40 mph (64.37 km/h)42.46 mph (68.33 km/h)
45 mph (72.42 km/h)47.77 mph (76.87 km/h)
50 mph (80.47 km/h)53.07 mph (85.41 km/h)
55 mph (88.51 km/h)58.38 mph (93.95 km/h)
60 mph (96.56 km/h)63.69 mph (102.49 km/h)
65 mph (104.61 km/h)68.99 mph (111.04 km/h)
70 mph (112.65 km/h)74.3 mph (119.58 km/h)
75 mph (120.7 km/h)79.61 mph (128.12 km/h)
80 mph (128.75 km/h)84.92 mph (136.66 km/h)
85 mph (136.79 km/h)90.22 mph (145.2 km/h)
90 mph (144.84 km/h)95.53 mph (153.74 km/h)
95 mph (152.89 km/h)100.84 mph (162.28 km/h)
100 mph (160.93 km/h)106.15 mph (170.82 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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