Allied Force
| Countries | Total | Killed | Wounded | Prisoners | Total | Casualties % |
| Belgium | 267,000 | 13,716 | 44,686 | 34,659 | 93,061 | 34.9 |
| British Empire | 8,904,467 | 908,371 | 2,090,212 | 191,652 | 3,190,235 | 35.8 |
| France | 8,410,000 | 1,357,800 | 4,266,000 | 537,000 | 6,160,800 | 76.3 |
| Greece | 230,000 | 5,000 | 21,000 | 1,000 | 17,000 | 11.7 |
| Italy | 5,615,000 | 650,000 | 947,000 | 600,000 | 2,197,000 | 39.1 |
| Japan | 800,000 | 300 | 907 | 3 | 1,210 | 0.2 |
| Romania | 750,000 | 335,706 | 120,000 | 80,000 | 535,706 | 71.4 |
| Russia | 12,000,000 | 1,700,000 | 4,950,000 | 2,500,000 | 9,150,000 | 76.3 |
| Serbia | 707,343 | 45,000 | 133,148 | 152,958 | 331,106 | 46.8 |
| United States | 4,355,000 | 126,000 | 234,300 | 4,500 | 364,800 | 8.2 |
| Total | 42,188,810 | 5,152,115 | 12,831,004 | 4,121,090 | 22,104,209 | 52.3 |
Central Powers
| Countries | Total | Killed | Wounded | Prisoners | Total | Casualties % |
| Austria-Hungary | 7,800,000 | 1,200,000 | 3,620,000 | 2,200,000 | 7,020,000 | 90.0 |
| Bulgaria | 1,200,000 | 87,500 | 152,390 | 27,029 | 266,919 | 22.2 |
| Germany | 11,000,000 | 1,773,7000 | 4,216,058 | 1,152,800 | 7,142,558 | 64.9 |
| Turkey | 2,850,000 | 325,000 | 400,000 | 250,000 | 975,000 | 34.2 |
| Total | 22,850,000 | 3,386,200 | 8,388,448 | 3,629,829 | 15,404,477 | 67.4 |
