Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
225/40r18 vs 225/45r17 Tire Comparison Side By Side
  225/40-18 225/45-17 Difference
Diameter inches (mm) 25.09 (637.2) 24.97 (634.3) -0.11 (-2.9) -0.5%
Width inches (mm) 8.86 (225) 8.86 (225) 0 (0) 0%
Circum. inches (mm) 78.81 (2001.82) 78.45 (1992.71) -0.36 (-9.11) -0.5%
Sidewall Height inches (mm) 3.54 (90) 3.99 (101.25) 0.44 (11.25) 12.5%
Revolutions per mile (km) 803.94 (499.54) 807.61 (501.83) 3.68 (2.28) 0.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.91 mph (32.04 km/h)
25 mph (40.23 km/h)24.89 mph (40.05 km/h)
30 mph (48.28 km/h)29.86 mph (48.06 km/h)
35 mph (56.33 km/h)34.84 mph (56.07 km/h)
40 mph (64.37 km/h)39.82 mph (64.08 km/h)
45 mph (72.42 km/h)44.8 mph (72.09 km/h)
50 mph (80.47 km/h)49.77 mph (80.1 km/h)
55 mph (88.51 km/h)54.75 mph (88.11 km/h)
60 mph (96.56 km/h)59.73 mph (96.12 km/h)
65 mph (104.61 km/h)64.7 mph (104.13 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
20552388257126852807289529913105326234203594373439884268448746264705499453966271
Better Fuel Economy Factory Ratios Increased Power

Most Popular 225/40-R18 Comparisons

To Top