how many members are in the armed forces
United States Armed Forces The projected active duty end strength in the armed forces for fiscal year 2017 was 1,281,900 people,[4] with an additional 801,200 people in the seven reserve components.[4] It is an all-volunteer military, but conscription through the Selective Service System can be enacted at the President's request and Congress' approval. All males ages 18 through 25 who are living in the United States are required to register with the Selective Service for a potential future draft.
United States military seniority A type of "positional seniority" exists for military officers who hold top leadership positions of the armed forces. For instance, the Chairman of the Joint Chiefs of Staff is considered the senior most officer of the entire United States military, even though it is possible that contemporaries of the same rank may have earlier dates of rank or time in service. Likewise, heads of various armed service branches are considered senior most within their service; unified commanders are also considered senior most in their respective regions yet not necessarily to each other.