Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
120/80r13 vs 120/70r13 Tire Comparison Side By Side
  120/80-13 120/70-13 Difference
Diameter inches (mm) 20.56 (522.2) 19.61 (498.2) -0.94 (-24) -4.6%
Width inches (mm) 4.72 (120) 4.72 (120) 0 (0) 0%
Circum. inches (mm) 64.59 (1640.54) 61.62 (1565.14) -2.97 (-75.4) -4.6%
Sidewall Height inches (mm) 3.78 (96) 3.31 (84) -0.47 (-12) -12.5%
Revolutions per mile (km) 980.98 (609.55) 1028.24 (638.92) 47.26 (29.36) 4.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.08 mph (30.71 km/h)
25 mph (40.23 km/h)23.85 mph (38.38 km/h)
30 mph (48.28 km/h)28.62 mph (46.06 km/h)
35 mph (56.33 km/h)33.39 mph (53.74 km/h)
40 mph (64.37 km/h)38.16 mph (61.42 km/h)
45 mph (72.42 km/h)42.93 mph (69.09 km/h)
50 mph (80.47 km/h)47.7 mph (76.77 km/h)
55 mph (88.51 km/h)52.47 mph (84.45 km/h)
60 mph (96.56 km/h)57.24 mph (92.12 km/h)
65 mph (104.61 km/h)62.01 mph (99.8 km/h)
70 mph (112.65 km/h)66.78 mph (107.48 km/h)
75 mph (120.7 km/h)71.55 mph (115.15 km/h)
80 mph (128.75 km/h)76.32 mph (122.83 km/h)
85 mph (136.79 km/h)81.09 mph (130.51 km/h)
90 mph (144.84 km/h)85.86 mph (138.18 km/h)
95 mph (152.89 km/h)90.63 mph (145.86 km/h)
100 mph (160.93 km/h)95.4 mph (153.54 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
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Better Fuel Economy Factory Ratios Increased Power

Most Popular 120/80-R13 Comparisons

To Top