How many people died in World War II?

How to get close to this number

Use the share of world population. The explanation gives it as roughly three percent, and world population at the time was around two and a half billion. Three percent of that is tens of millions. Converting a historical death toll into a share of the living population is both a better estimation route and a better way to feel the scale.

The composition is the part that surprises people who think of war as soldiers dying. Civilian deaths outnumber military ones, through bombing, famine, disease, forced displacement and genocide. Modern industrial war kills more people away from the fighting than in it, and any war death toll that counts only combatants understates it by more than half.

The uncertainty is concentrated geographically, which the explanation states directly: two countries account for well over half the total, and record-keeping in both makes precision impossible. That is why published totals range across fifteen million — the disagreement is not about the war in western Europe, where records are good, but about the parts of the war that were largest.