Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
285/65r18 vs 305/65r18 Tire Comparison Side By Side
  285/65-18 305/65-18 Difference
Diameter inches (mm) 32.59 (827.7) 33.61 (853.7) 1.02 (26) 3.1%
Width inches (mm) 11.22 (285) 12.01 (305) 0.79 (20) 7%
Circum. inches (mm) 102.37 (2600.3) 105.59 (2681.98) 3.22 (81.68) 3.1%
Sidewall Height inches (mm) 7.29 (185.25) 7.81 (198.25) 0.51 (13) 7%
Revolutions per mile (km) 618.91 (384.57) 600.06 (372.86) -18.85 (-11.71) -3%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.63 mph (33.2 km/h)
25 mph (40.23 km/h)25.79 mph (41.5 km/h)
30 mph (48.28 km/h)30.94 mph (49.8 km/h)
35 mph (56.33 km/h)36.1 mph (58.1 km/h)
40 mph (64.37 km/h)41.26 mph (66.4 km/h)
45 mph (72.42 km/h)46.41 mph (74.7 km/h)
50 mph (80.47 km/h)51.57 mph (83 km/h)
55 mph (88.51 km/h)56.73 mph (91.29 km/h)
60 mph (96.56 km/h)61.88 mph (99.59 km/h)
65 mph (104.61 km/h)67.04 mph (107.89 km/h)
70 mph (112.65 km/h)72.2 mph (116.19 km/h)
75 mph (120.7 km/h)77.36 mph (124.49 km/h)
80 mph (128.75 km/h)82.51 mph (132.79 km/h)
85 mph (136.79 km/h)87.67 mph (141.09 km/h)
90 mph (144.84 km/h)92.83 mph (149.39 km/h)
95 mph (152.89 km/h)97.98 mph (157.69 km/h)
100 mph (160.93 km/h)103.14 mph (165.99 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
15271774191019952086215122222307242425412671277529633171333334373496371040094659
Better Fuel Economy Factory Ratios Increased Power

Most Popular 285/65-R18 Comparisons

To Top