World War I (1914–1918)
- Human Losses: The total death toll is estimated at 15–20 million, including military personnel and civilians. Around 9 million military deaths occurred, while civilian deaths ranged from 6 to 11 million, caused by famine, disease, and military operations. Over 21 million soldiers were wounded.
- Economic Losses: The war's financial cost is estimated at $208 billion (adjusted for inflation). Widespread destruction of infrastructure and property occurred, particularly in Europe.
World War II (1939–1945)
- Human Losses: An estimated 70–85 million people died, representing about 3% of the global population at the time. Military deaths accounted for 21–25 million, while civilian deaths totaled 50–55 million. These civilian deaths include the Holocaust (6 million Jews) and other genocides. Tens of millions of people were wounded.
- Economic Losses: The war's cost exceeded $1 trillion in 1945 USD, equivalent to approximately $15 trillion today. Cities, industries, and infrastructure in Europe, Asia, and parts of North Africa were heavily damaged or destroyed.
