"Established by December 1914, the Western Front was a network of trenches that stretched across eastern France and a section of western Belgium. The Western Front ran approximately 400 miles (645 km), reaching from the North Sea to the border of Switzerland."
Hamilton, John. Events Leading to World War I. Edina, MN: ABDO, 2004. Print.
"The length of the front in the East was much longer than in the West. The theatre of war was roughly delimited by the Baltic Sea in the West and Moscow in the East, a distance of 1,200 kilometers, and Saint Petersburg in the North and the Black Sea in the South, a distance of more than 1,600 kilometers."