Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
245/45r20 vs 275/40r20 Tire Comparison Side By Side
  245/45-20 275/40-20 Difference
Diameter inches (mm) 28.68 (728.5) 28.66 (728) -0.02 (-0.5) -0.1%
Width inches (mm) 9.65 (245) 10.83 (275) 1.18 (30) 12.2%
Circum. inches (mm) 90.1 (2288.65) 90.04 (2287.08) -0.06 (-1.57) -0.1%
Sidewall Height inches (mm) 4.34 (110.25) 4.33 (110) -0.01 (-0.25) -0.2%
Revolutions per mile (km) 703.18 (436.94) 703.67 (437.24) 0.48 (0.3) 0.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.99 mph (32.16 km/h)
25 mph (40.23 km/h)24.98 mph (40.21 km/h)
30 mph (48.28 km/h)29.98 mph (48.25 km/h)
35 mph (56.33 km/h)34.98 mph (56.29 km/h)
40 mph (64.37 km/h)39.97 mph (64.33 km/h)
45 mph (72.42 km/h)44.97 mph (72.37 km/h)
50 mph (80.47 km/h)49.97 mph (80.41 km/h)
55 mph (88.51 km/h)54.96 mph (88.45 km/h)
60 mph (96.56 km/h)59.96 mph (96.49 km/h)
65 mph (104.61 km/h)64.96 mph (104.54 km/h)
70 mph (112.65 km/h)69.95 mph (112.58 km/h)
75 mph (120.7 km/h)74.95 mph (120.62 km/h)
80 mph (128.75 km/h)79.95 mph (128.66 km/h)
85 mph (136.79 km/h)84.94 mph (136.7 km/h)
90 mph (144.84 km/h)89.94 mph (144.74 km/h)
95 mph (152.89 km/h)94.93 mph (152.78 km/h)
100 mph (160.93 km/h)99.93 mph (160.82 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
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