The total number of casualties in Russia were 9,150,000. Russia is at the top of the list for most casualties lost
There are conflicting numbers out there, but a safe estimate was a total of 1,200,000. That's about 420,000 British and 200,000 French. German casualties were estimated to 500,000 with incidentals of another 20,000 at least.
Allied Military Casualties: 14,276,800 Allied Civilian Casualties: 25,686,900 Allied Total Casualties: 39,963,700
1.1 million German casualties in WW1.
* British Casualties: 1,547 aircraft; 27,450 dead civilians, 32,138 wounded civilians; 498 RAF pilots * German Casualties: 1,887 aircraft
There were a total of 2,403 American casualties, including 68 civilians. Source: Military.com
Gettysburg, lasting three days, had the highest total number of casualties. Antietam, lasting one day, had the highest single-day total.
There were about 300,000 million casualties in world war 1.