Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
255/50r21 vs 245/40r22 Tire Comparison Side By Side
  255/50-21 245/40-22 Difference
Diameter inches (mm) 31.04 (788.4) 29.72 (754.8) -1.32 (-33.6) -4.3%
Width inches (mm) 10.04 (255) 9.65 (245) -0.39 (-10) -3.9%
Circum. inches (mm) 97.51 (2476.83) 93.36 (2371.27) -4.16 (-105.56) -4.3%
Sidewall Height inches (mm) 5.02 (127.5) 3.86 (98) -1.16 (-29.5) -23.1%
Revolutions per mile (km) 649.76 (403.74) 678.68 (421.71) 28.92 (17.97) 4.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.15 mph (30.82 km/h)
25 mph (40.23 km/h)23.93 mph (38.52 km/h)
30 mph (48.28 km/h)28.72 mph (46.22 km/h)
35 mph (56.33 km/h)33.51 mph (53.93 km/h)
40 mph (64.37 km/h)38.3 mph (61.63 km/h)
45 mph (72.42 km/h)43.08 mph (69.33 km/h)
50 mph (80.47 km/h)47.87 mph (77.04 km/h)
55 mph (88.51 km/h)52.66 mph (84.74 km/h)
60 mph (96.56 km/h)57.44 mph (92.45 km/h)
65 mph (104.61 km/h)62.23 mph (100.15 km/h)
70 mph (112.65 km/h)67.02 mph (107.85 km/h)
75 mph (120.7 km/h)71.8 mph (115.56 km/h)
80 mph (128.75 km/h)76.59 mph (123.26 km/h)
85 mph (136.79 km/h)81.38 mph (130.96 km/h)
90 mph (144.84 km/h)86.16 mph (138.67 km/h)
95 mph (152.89 km/h)90.95 mph (146.37 km/h)
100 mph (160.93 km/h)95.74 mph (154.08 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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