Over the four-day period the Allies lost probably 54,000 killed and wounded, although accurate figures are extremely hard to calculate. As for the French, their battle casualties were probably in excess of 38,000, but a further 30,000 fell into Allied hands during the 19th. Additionally, 5,000German troops defected to the enemy during the battle. The French losses included six general officers killed, a further twelve wounded, and no less than 36 fell into Allied hands as prisoners of war, a fate also shared by the King of Saxony. In terms of materiel, Napoleon abandoned at least 325 cannon, most of his trains and transport columns and large quantities of military stores.
Destruction of the causeway over the Elster, climax of Leipzig
This long battle was the severest of the Napoleonic Wars save only for Borodino; over 200,000 rounds of artillery ammunition were discharged, and by the 19th the French stocks were down to a mere 20,000. The ultimate result was to destroy what was left of the French Empire east of the Rhine. Bavaria had already deserted Napoleon's cause; Saxony (apart from Dresden where St. Cyr and Lobau held out until November 11) was occupied by Allied forces and forced into a form of agreement with the Allies. Within a few days the ruler of Wurttemberg was forced to follow Bavaria's lead, and this event inevitably led to the remaining principalities of the Confederation following suit. Militarily, Leipzig dealt a heavy blow to Napoleon's martial reputation, and eventually destroyed over two thirds of France's hard-found forces outside Spain. Politically, it marked the emergence of Prussia as a leading power in Germany once more, and prepared the way for the birth of modern Europe.
the Napoleonic eagles had been forced to bow out of central and eastern Europe
~ D. Chandler, The Campaigns of Napoleon, p. 936