Columns of conscripts lug their suitcases as they are about to enter military life. Soon they’ll wear the same field-grey uniforms, learning to march and shoot. After Germany re-introduced conscription in 1935 in defiance of the Treaty of Versailles, a total of about 18.2 million men served in the Wehrmacht until the defeat in 1945. The Wehrmacht suffered about 10 million casualties during WW2, a combination of about 2 million killed in action, 3 million missing in action (most likely dead), and 5 million wounded in action. As WW2 intensified, Kriegsmarine and Luftwaffe personnel were increasingly transferred to the Army, and “voluntary” enlistments in the SS were stepped up as well. Following the defeat in Battle of Stalingrad in early 1943, fitness standards for Wehrmacht recruits were drastically lowered, with the regime going so far as to create “special diet” battalions for men with severe stomach ailments. Rear-echelon personnel were sent to front-line duty wherever possible, especially during the last two years of the war.
With the introduction of military conscription in 1935, the 1914 class of 21 year olds were called up. Each conscripted annual intake (in peacetime) could be expected to bring in around 300,000 men, reduced to 250,000 for the 1916-18 classes due to the lower birth rate during WW1. Those who had experienced no military training (the so called ‘white years’ classes of 1901 to 1913, due to the reduction of the Army after WW1) were available as a untrained reserve, listed as Class 2 reservists. General Fretter-Pico complained in 1944 that after the Waffen-SS, the Luftwaffe, the Kriegsmarine, and the Heer technical services had combed through and picked out the best of recruits, the poor bloody infantry was left with whatever recruits there was. The same complaint could be heard in the US Army, though.
By May 1940 the call-up classes for 1919 and 1920 (that is to say those 21 and 20) were entering the Ersatzheer to begin training, while the earlier classes of 1915-18 were already in the Field Army. Generally someone born in 1919 or 1920 wouldn’t have participated in the French campaign of 1940, but would’ve been readily trained and deployed for Operation Barbarossa in 1941. By early June 1941, after only 3 months of training, 80,000 men of the 1921 Class were formed into reinforcement Marschbataillone for the upcoming campaign in USSR.
The conscription age was lowered as the war progressed, and the losses had to be replaced. Before the outbreak of the war, it was 21, but was lowered to 20 in the later part of 1939. It was lowered yet again after the launch of Operation Barbarossa, calling up 19-years olds. In late 1942, it was the 18-years olds turn, and a year later the 17-years olds. By the end of 1944, the conscription age was lowered a final time, calling up the 16-years olds of the 1928 and 1929 classes. Of those, about 12,000 were killed in action. It isn’t just a cliché in movies and books when combat veterans comment that new reinforcements are just kids – “milk-beards”.
Of the men born in 1914-1924 and called up for service, about 35 % (on average) of each year class didn’t survive the war. Worst hit was the class of 1921, of which 38.95 % died (286,380 out of 735,206 men born that year). Most of them had been called up in 1941, and I guess the majority of them went to the meat grinder on the Eastern Front.