Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
305/30r21 vs 295/30r21 Tire Comparison Side By Side
  305/30-21 295/30-21 Difference
Diameter inches (mm) 28.2 (716.4) 27.97 (710.4) -0.24 (-6) -0.8%
Width inches (mm) 12.01 (305) 11.61 (295) -0.39 (-10) -3.3%
Circum. inches (mm) 88.61 (2250.64) 87.87 (2231.79) -0.74 (-18.85) -0.8%
Sidewall Height inches (mm) 3.6 (91.5) 3.48 (88.5) -0.12 (-3) -3.3%
Revolutions per mile (km) 715.06 (444.32) 721.1 (448.07) 6.04 (3.75) 0.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.83 mph (31.92 km/h)
25 mph (40.23 km/h)24.79 mph (39.9 km/h)
30 mph (48.28 km/h)29.75 mph (47.88 km/h)
35 mph (56.33 km/h)34.71 mph (55.86 km/h)
40 mph (64.37 km/h)39.66 mph (63.83 km/h)
45 mph (72.42 km/h)44.62 mph (71.81 km/h)
50 mph (80.47 km/h)49.58 mph (79.79 km/h)
55 mph (88.51 km/h)54.54 mph (87.77 km/h)
60 mph (96.56 km/h)59.5 mph (95.75 km/h)
65 mph (104.61 km/h)64.46 mph (103.73 km/h)
70 mph (112.65 km/h)69.41 mph (111.71 km/h)
75 mph (120.7 km/h)74.37 mph (119.69 km/h)
80 mph (128.75 km/h)79.33 mph (127.67 km/h)
85 mph (136.79 km/h)84.29 mph (135.65 km/h)
90 mph (144.84 km/h)89.25 mph (143.63 km/h)
95 mph (152.89 km/h)94.2 mph (151.61 km/h)
100 mph (160.93 km/h)99.16 mph (159.59 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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