Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
235/45r18 vs 215/45r18 Tire Comparison Side By Side
  235/45-18 215/45-18 Difference
Diameter inches (mm) 26.33 (668.7) 25.62 (650.7) -0.71 (-18) -2.7%
Width inches (mm) 9.25 (235) 8.46 (215) -0.79 (-20) -8.5%
Circum. inches (mm) 82.71 (2100.78) 80.48 (2044.23) -2.23 (-56.55) -2.7%
Sidewall Height inches (mm) 4.16 (105.75) 3.81 (96.75) -0.35 (-9) -8.5%
Revolutions per mile (km) 766.07 (476.01) 787.26 (489.18) 21.19 (13.17) 2.8%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.46 mph (31.32 km/h)
25 mph (40.23 km/h)24.33 mph (39.15 km/h)
30 mph (48.28 km/h)29.19 mph (46.98 km/h)
35 mph (56.33 km/h)34.06 mph (54.81 km/h)
40 mph (64.37 km/h)38.92 mph (62.64 km/h)
45 mph (72.42 km/h)43.79 mph (70.47 km/h)
50 mph (80.47 km/h)48.65 mph (78.3 km/h)
55 mph (88.51 km/h)53.52 mph (86.13 km/h)
60 mph (96.56 km/h)58.38 mph (93.96 km/h)
65 mph (104.61 km/h)63.25 mph (101.79 km/h)
70 mph (112.65 km/h)68.12 mph (109.62 km/h)
75 mph (120.7 km/h)72.98 mph (117.45 km/h)
80 mph (128.75 km/h)77.85 mph (125.28 km/h)
85 mph (136.79 km/h)82.71 mph (133.11 km/h)
90 mph (144.84 km/h)87.58 mph (140.94 km/h)
95 mph (152.89 km/h)92.44 mph (148.77 km/h)
100 mph (160.93 km/h)97.31 mph (156.6 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
20032327250626172737282229163026318033333504364038874160437345104587486852606113
Better Fuel Economy Factory Ratios Increased Power

Most Popular 235/45-R18 Comparisons

To Top