Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
235/50r18 vs 255/45r18 Tire Comparison Side By Side
  235/50-18 255/45-18 Difference
Diameter inches (mm) 27.25 (692.2) 27.04 (686.7) -0.22 (-5.5) -0.8%
Width inches (mm) 9.25 (235) 10.04 (255) 0.79 (20) 8.5%
Circum. inches (mm) 85.61 (2174.61) 84.93 (2157.33) -0.68 (-17.28) -0.8%
Sidewall Height inches (mm) 4.63 (117.5) 4.52 (114.75) -0.11 (-2.75) -2.3%
Revolutions per mile (km) 740.06 (459.85) 745.99 (463.53) 5.93 (3.68) 0.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.84 mph (31.93 km/h)
25 mph (40.23 km/h)24.8 mph (39.91 km/h)
30 mph (48.28 km/h)29.76 mph (47.9 km/h)
35 mph (56.33 km/h)34.72 mph (55.88 km/h)
40 mph (64.37 km/h)39.68 mph (63.86 km/h)
45 mph (72.42 km/h)44.64 mph (71.85 km/h)
50 mph (80.47 km/h)49.6 mph (79.83 km/h)
55 mph (88.51 km/h)54.56 mph (87.81 km/h)
60 mph (96.56 km/h)59.52 mph (95.79 km/h)
65 mph (104.61 km/h)64.48 mph (103.78 km/h)
70 mph (112.65 km/h)69.44 mph (111.76 km/h)
75 mph (120.7 km/h)74.4 mph (119.74 km/h)
80 mph (128.75 km/h)79.36 mph (127.72 km/h)
85 mph (136.79 km/h)84.32 mph (135.71 km/h)
90 mph (144.84 km/h)89.28 mph (143.69 km/h)
95 mph (152.89 km/h)94.25 mph (151.67 km/h)
100 mph (160.93 km/h)99.21 mph (159.66 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
18982205237524802593267427632868301331593320344936843942414442734346461349845792
Better Fuel Economy Factory Ratios Increased Power

Most Popular 235/50-R18 Comparisons

To Top