Chain of Command

Following are the basic building block of all Army organizations –

• Squad – Squad is a small military unit, which consists of 8 to 13 soldiers. It is led by a staff sergeant or sergeant.
• Platoon – Platoon is a military unit, which consists of 2 to 4 squads or 16 to 50 soldiers. It is typically commanded by a lieutenant or platoon leader.

• Company – Company is a military unit, which consists of 3 to 5 platoons or 75 to 200 soldiers. It is usually commanded by a Captain or a Major.

• Battalion – Battalion is a military unit, which consists of 2 to 7 companies or 300 to 1,300 soldiers. It is commanded by either a Lieutenant Colonel or Colonel.
• Brigade – Brigade is a military unit that is typically composed of 2 to 5 battalions or 3,000 to 5,000 soldiers. It is led by a colonel with a command sergeant major as senior NCO.
• Division – Division is a large military unit consisting of 3 brigades or 10,000 to 15,000 soldiers. It is led by a Major General.
• Corps – Corps is either a large formation or an administrative grouping of troops, which consists of 2 to 5 divisions or 20,000 to 45,000 soldiers. It is typically commanded by a Lieutenant General.
• Army – Army, Field Army or Area Army is a term used by many national armed forces for a formation superior to Corps. It consists of at least 2 corps or 80,000 to 200,000 soldiers. It is commanded by a Lieutenant General or General.
• Army Group – It is a military organization consisting of several field armies and generally includes 400,000 to 1,500,000 soldiers. It is handled by a Field Marshal or full General.
• Army Region – It is a military formation larger than an Army Group and generally consists of 1,000,000 to 3,000,000 soldiers. It is commanded by a Field Marshal.

US Army Ranks
Following are the hierarchy of US army in ascending order i.e. smaller rank to higher rank –