Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
305/45r20 vs 275/45r20 Tire Comparison Side By Side
  305/45-20 275/45-20 Difference
Diameter inches (mm) 30.81 (782.5) 29.74 (755.5) -1.06 (-27) -3.5%
Width inches (mm) 12.01 (305) 10.83 (275) -1.18 (-30) -9.8%
Circum. inches (mm) 96.78 (2458.3) 93.44 (2373.47) -3.34 (-84.82) -3.5%
Sidewall Height inches (mm) 5.4 (137.25) 4.87 (123.75) -0.53 (-13.5) -9.8%
Revolutions per mile (km) 654.66 (406.79) 678.05 (421.32) 23.4 (14.54) 3.6%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.31 mph (31.08 km/h)
25 mph (40.23 km/h)24.14 mph (38.85 km/h)
30 mph (48.28 km/h)28.96 mph (46.61 km/h)
35 mph (56.33 km/h)33.79 mph (54.38 km/h)
40 mph (64.37 km/h)38.62 mph (62.15 km/h)
45 mph (72.42 km/h)43.45 mph (69.92 km/h)
50 mph (80.47 km/h)48.27 mph (77.69 km/h)
55 mph (88.51 km/h)53.1 mph (85.46 km/h)
60 mph (96.56 km/h)57.93 mph (93.23 km/h)
65 mph (104.61 km/h)62.76 mph (101 km/h)
70 mph (112.65 km/h)67.58 mph (108.77 km/h)
75 mph (120.7 km/h)72.41 mph (116.54 km/h)
80 mph (128.75 km/h)77.24 mph (124.31 km/h)
85 mph (136.79 km/h)82.07 mph (132.07 km/h)
90 mph (144.84 km/h)86.89 mph (139.84 km/h)
95 mph (152.89 km/h)91.72 mph (147.61 km/h)
100 mph (160.93 km/h)96.55 mph (155.38 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
17262005215922542357243025112607273928713018313533483583376738843950419345305265
Better Fuel Economy Factory Ratios Increased Power

Most Popular 305/45-R20 Comparisons

To Top