Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
215/50r12 vs 215/40r14 Tire Comparison Side By Side
  215/50-12 215/40-14 Difference
Diameter inches (mm) 20.46 (519.8) 20.77 (527.6) 0.31 (7.8) 1.5%
Width inches (mm) 8.46 (215) 8.46 (215) 0 (0) 0%
Circum. inches (mm) 64.29 (1633) 65.26 (1657.5) 0.96 (24.5) 1.5%
Sidewall Height inches (mm) 4.23 (107.5) 3.39 (86) -0.85 (-21.5) -20%
Revolutions per mile (km) 985.51 (612.37) 970.94 (603.32) -14.57 (-9.05) -1.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.3 mph (32.67 km/h)
25 mph (40.23 km/h)25.38 mph (40.84 km/h)
30 mph (48.28 km/h)30.45 mph (49 km/h)
35 mph (56.33 km/h)35.53 mph (57.17 km/h)
40 mph (64.37 km/h)40.6 mph (65.34 km/h)
45 mph (72.42 km/h)45.68 mph (73.51 km/h)
50 mph (80.47 km/h)50.75 mph (81.67 km/h)
55 mph (88.51 km/h)55.83 mph (89.84 km/h)
60 mph (96.56 km/h)60.9 mph (98.01 km/h)
65 mph (104.61 km/h)65.98 mph (106.18 km/h)
70 mph (112.65 km/h)71.05 mph (114.34 km/h)
75 mph (120.7 km/h)76.13 mph (122.51 km/h)
80 mph (128.75 km/h)81.2 mph (130.68 km/h)
85 mph (136.79 km/h)86.28 mph (138.85 km/h)
90 mph (144.84 km/h)91.35 mph (147.01 km/h)
95 mph (152.89 km/h)96.43 mph (155.18 km/h)
100 mph (160.93 km/h)101.5 mph (163.35 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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