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 245/50r12 Tire Comparison Side By Side
  215/50-12 245/50-12 Difference
Diameter inches (mm) 20.46 (519.8) 21.65 (549.8) 1.18 (30) 5.8%
Width inches (mm) 8.46 (215) 9.65 (245) 1.18 (30) 14%
Circum. inches (mm) 64.29 (1633) 68 (1727.25) 3.71 (94.25) 5.8%
Sidewall Height inches (mm) 4.23 (107.5) 4.82 (122.5) 0.59 (15) 14%
Revolutions per mile (km) 985.51 (612.37) 931.74 (578.95) -53.77 (-33.41) -5.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)21.15 mph (34.04 km/h)
25 mph (40.23 km/h)26.44 mph (42.56 km/h)
30 mph (48.28 km/h)31.73 mph (51.07 km/h)
35 mph (56.33 km/h)37.02 mph (59.58 km/h)
40 mph (64.37 km/h)42.31 mph (68.09 km/h)
45 mph (72.42 km/h)47.6 mph (76.6 km/h)
50 mph (80.47 km/h)52.89 mph (85.11 km/h)
55 mph (88.51 km/h)58.17 mph (93.62 km/h)
60 mph (96.56 km/h)63.46 mph (102.13 km/h)
65 mph (104.61 km/h)68.75 mph (110.64 km/h)
70 mph (112.65 km/h)74.04 mph (119.16 km/h)
75 mph (120.7 km/h)79.33 mph (127.67 km/h)
80 mph (128.75 km/h)84.62 mph (136.18 km/h)
85 mph (136.79 km/h)89.91 mph (144.69 km/h)
90 mph (144.84 km/h)95.19 mph (153.2 km/h)
95 mph (152.89 km/h)100.48 mph (161.71 km/h)
100 mph (160.93 km/h)105.77 mph (170.22 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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