WW1 Casualties The number of WWI casualties amounts to about 40 million, 19 million were deaths and 21 million wounded.This figure includes 9.7 million military deaths and 10 million civilian deaths.The allied Powers lost 5 million soldiers and the Central Powers lost 4 million. These figures are, however, debatable due to the fact that miltary casualty statistics also include combat-related deaths as well as deaths caused by accidents, disease and being a prisoner of war.