Allied forces:

Great Britain + Commonwealth452,000
France250,000
USA295,000
USSR
13,600,000
Belgium10,000
Holland10,000
Norway10,000
Poland120,000
Greece20,000
Yugoslavia300,000
Czechoslovakia20,000
China (from 1937 on)3,500,000
Total18,587,000


Axis forces:

Germany 3,250,000
Austria 230,000
Italy 330,000
Rumania 200,000
Hungary 120,000
Bulgaria 10,000
Finland 90,000
Japan 1,700,000
Total 5,930,000

Total military casualties Allies + Axis forces = 24,517,000

Total civilian + military casualties (Allies + Axis) = 55,014,000