The total number of casualties—killed and wounded—at the Battle of Waterloo was about 47,000. This figure combines losses suffered by Napoleon’s French army with those of Wellington’s Anglo-allied army and Blücher’s Prussian forces on 18 June 1815.
Waterloo was exceptionally costly because the fighting lasted roughly ten hours and involved infantry assaults, massed cavalry charges, artillery fire, and the arrival of substantial Prussian reinforcements. Wellington’s army suffered approximately 17,000 killed or wounded, while the Prussians lost around 7,000. French losses are generally estimated at about 24,000–26,000 killed or wounded, with thousands more captured or missing.
The exact total varies by source because historians count casualties differently. Some figures include prisoners, missing soldiers, or losses during the wider Waterloo campaign, while the commonly quoted 47,000 figure refers broadly to men killed or wounded in the battle. Waterloo was Napoleon’s final major engagement and ended his Hundred Days return from exile.