Tire Size Calculator

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Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
265/35r21 vs 275/40r20 Tire Comparison Side By Side
  265/35-21 275/40-20 Difference
Diameter inches (mm) 28.3 (718.9) 28.66 (728) 0.36 (9.1) 1.3%
Width inches (mm) 10.43 (265) 10.83 (275) 0.39 (10) 3.8%
Circum. inches (mm) 88.92 (2258.49) 90.04 (2287.08) 1.13 (28.59) 1.3%
Sidewall Height inches (mm) 3.65 (92.75) 4.33 (110) 0.68 (17.25) 18.6%
Revolutions per mile (km) 712.57 (442.77) 703.67 (437.24) -8.91 (-5.53) -1.2%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.25 mph (32.59 km/h)
25 mph (40.23 km/h)25.32 mph (40.74 km/h)
30 mph (48.28 km/h)30.38 mph (48.89 km/h)
35 mph (56.33 km/h)35.44 mph (57.04 km/h)
40 mph (64.37 km/h)40.51 mph (65.19 km/h)
45 mph (72.42 km/h)45.57 mph (73.34 km/h)
50 mph (80.47 km/h)50.63 mph (81.49 km/h)
55 mph (88.51 km/h)55.7 mph (89.63 km/h)
60 mph (96.56 km/h)60.76 mph (97.78 km/h)
65 mph (104.61 km/h)65.82 mph (105.93 km/h)
70 mph (112.65 km/h)70.89 mph (114.08 km/h)
75 mph (120.7 km/h)75.95 mph (122.23 km/h)
80 mph (128.75 km/h)81.01 mph (130.38 km/h)
85 mph (136.79 km/h)86.08 mph (138.53 km/h)
90 mph (144.84 km/h)91.14 mph (146.67 km/h)
95 mph (152.89 km/h)96.2 mph (154.82 km/h)
100 mph (160.93 km/h)101.27 mph (162.97 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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