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.
Ottoman casualties of World War I
If looked at without breakdowns, the total Ottoman losses run almost as high as 25% of the population — approximately 5 million out of population of 21 million. To be more exact, the 1914 census gave 20,975,345 as the population size, of which 15,044,846 was part of the Muslim millet, 187,073 part of the Jewish millet, 186,152 not belonging to any millet, and the remaining 5,557,274 shared by other millets.