Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
34/12.5r18 vs 275/65r18 Tire Comparison Side By Side
  34/12.5-18 275/65-18 Difference
Diameter inches (mm) 34.03 (864.24) 32.07 (814.7) -1.95 (-49.54) -5.7%
Width inches (mm) 12.52 (318) 10.83 (275) -1.69 (-43) -13.5%
Circum. inches (mm) 106.89 (2715.09) 100.77 (2559.46) -6.13 (-155.63) -5.7%
Sidewall Height inches (mm) 8.01 (203.52) 7.04 (178.75) -0.98 (-24.77) -12.2%
Revolutions per mile (km) 592.74 (368.31) 628.78 (390.71) 36.04 (22.4) 6.1%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)18.85 mph (30.34 km/h)
25 mph (40.23 km/h)23.57 mph (37.93 km/h)
30 mph (48.28 km/h)28.28 mph (45.51 km/h)
35 mph (56.33 km/h)32.99 mph (53.1 km/h)
40 mph (64.37 km/h)37.71 mph (60.68 km/h)
45 mph (72.42 km/h)42.42 mph (68.27 km/h)
50 mph (80.47 km/h)47.13 mph (75.85 km/h)
55 mph (88.51 km/h)51.85 mph (83.44 km/h)
60 mph (96.56 km/h)56.56 mph (91.03 km/h)
65 mph (104.61 km/h)61.27 mph (98.61 km/h)
70 mph (112.65 km/h)65.99 mph (106.2 km/h)
75 mph (120.7 km/h)70.7 mph (113.78 km/h)
80 mph (128.75 km/h)75.41 mph (121.37 km/h)
85 mph (136.79 km/h)80.13 mph (128.95 km/h)
90 mph (144.84 km/h)84.84 mph (136.54 km/h)
95 mph (152.89 km/h)89.55 mph (144.12 km/h)
100 mph (160.93 km/h)94.27 mph (151.71 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
16001859200220902186225423292417254026622799290731053323349336023663388842014882
Better Fuel Economy Factory Ratios Increased Power

Most Popular 34/12.5-R18 Comparisons

To Top