During ww2, were there more civilian or battle-related deaths?

Historians like original source documents: after action combat reports filled out by unit commanders, ration requests, orders for weapons and other such documents. However, you must keep the time period in which these documents were created. What could be valid in one time period in history where 1 weapon ordered was the same as 1 person in the ranks while in other times 500 items could be ordered but they went to both field personnel and into stock in various places but only 50 actual soldiers in the field ever got them. Sometimes these equipment and food ration records give accurate records of personnel before and after an engagement.

This is not designed to be an exhaustive inclusive list of all wars. Record keeping of figures is good from the 1200s onward for European nations. Prior to that valid records are spotty. Roman era records as well as Greek records in some cases can be verified. Most have to be calculated estimates within valid realms of probability. Some Chinese record keeping go back a lot further are also good. Modern Chinese records are hard to establish due to the many changes of governments that have occurred in China over the past 150 years. Records for other locations on Terra Firma is almost nonexistent prior to a European arrival.

Civilian casualty figures for most wars are impossible to verify. Most historians and governments guessed at them. Some guess due in part that the records of the people living in an area were themselves destroyed, and sometimes they were never counted to hide the true losses from their own people as to the number killed as well as to keep those numbers from enemy.