The US X Corps and the ROK I Corps reported a total of 10,495 battle casualties: 4,385 US Marines, 3,163 US Army personnel, 2,812 South Koreans attached to American formations and 78 British Royal Marines.[1]:347 The 1st Marine Division also reported 7,338 non-battle casualties due to the cold weather, adding up to a total of 17,833 casualties.[1]:345
Appleman, Roy (1990). Escaping the Trap: The US Army X Corps in Northeast Korea, 1950. Military History Series. Texas A&M University. ISBN 9780890963951.
在包围圈内部的美军大概有三万人，主要是陆战第一师（从损失数字中陆一师的比例可见）。(Appleman, pp. 24)
我前两天贴过一个美军对42个被打残的步兵营（其实还加上5个全灭的）的分析，部队崩溃点大概发生在未补充的兵员损失达到30-40％的水平。
所以陆一师在长津湖的损失以师的规模，在美军的作战史上是极为严重的。该师在海空军火力掩护下撤到后方补充了两个月损失之后才重返前线。