World War I
* Total number of troops mobilized: Approximately 70 million
* Central Powers:
- Germany: 13,250,000
- Austria-Hungary: 9,000,000
- Ottoman Empire: 2,850,000
- Bulgaria: 1,200,000
- Total: approximately 26,300,000
* Allied Powers:
- Russian Empire: 12,000,000
- France: 8,950,000
- British Empire: 8,904,467
- Italy: 5,615,000
- United States: 4,355,000
- Serbia: 1,250,000
- Belgium: 267,000
- Montenegro: 50,000
- Japan: 840,000
- Romania: 1,200,000
- Greece: 230,000
- Portugal: 100,000
- Total: approximately 45,700,000
World War II
* Total number of troops mobilized: Approximately 100 million
* Axis Powers:
- Germany: 18,250,000
- Japan: 11,000,000
- Italy: 5,000,000
- Hungary: 1,500,000
- Romania: 1,250,000
- Bulgaria: 450,000
- Finland: 350,000
- Croatia: 230,000
- Slovakia: 125,000
- Total: approximately 39,200,000
* Allied Powers:
- Soviet Union: 34,476,700
- United States: 16,112,566
- United Kingdom: 8,862,676
- China: 8,000,000
- France: 5,000,000
- Poland: 1,500,000
- Canada: 1,159,000
- Italy (post-1943): 1,000,000
- Brazil: 100,000
- Yugoslavia: 850,000
- Czechoslovakia: 450,000
- Greece: 400,000
- Netherlands: 395,560
- Belgium: 385,000
- Australia: 335,369
- New Zealand: 200,000
- South Africa: 135,000
- India: 2,500,000
- Mexico: 300,000
- Norway: 350,000
- Denmark: 100,000
- Total: approximately 78,100,00