World War I casualties
The total number of military and civilian casualties in World War I were about 40 million: estimates range from 15 to 19 million deaths and about 23 million wounded military personnel, ranking it among the deadliest conflicts in human history.
German casualties in World War II
Statistics for German World War II military casualties are divergent and contradictory. The wartime military casualty figures compiled by German High Command, up until January 31, 1945, are often cited by military historians when covering individual campaigns in the war. A recent study by the German historian Rüdiger Overmans found that the German High Command statistics are not reliable, he estimated German military dead at 5.3 million, including 900,000 men conscripted from outside of Germany's 1937 borders, in Austria and in east-central Europe. The German government still maintains that its records list 4.3 million dead and missing military personnel. Civilian deaths during the war include air raid deaths, estimates of German civilians killed only by Allied strategic bombing have ranged from around 350,000 to 500,000.
Civilian deaths, due to the flight and expulsion of Germans and the forced labor of Germans in the Soviet Union are disputed and range from 500,000 to over 2.0 million. According to the German government "Suchdienste" (Search Service) there were 300,000 German victims (including Jews) of Nazi racial, political and religious persecution. This statistic does not include 200,000 German people with disabilities who were murdered in the Action T4 and  Action 14f13 euthanasia programs.