Rank -- Commissioned Officers
Grade Army Marine Corps Navy Air Force
O1 2nd Lieutenant 2nd Lieutenant Ensign 2nd Lieutenant
O2 1st Lieutenant 1st Lieutenant Lieutenant Junior Grade 1st Lieutenant
O3 Captain Captain Lieutenant Captain
O4 Major Major Lieutenant Commander Major
O5 Lieutenant Colonel Lieutenant Colonel Commander Lieutenant Colonel
O6 Colonel Colonel Captain Colonel
O7 Brigadier General Brigadier General Rear Admiral Lower Half Brigadier General
O8 Major General Major General Rear Admiral Upper Half Major General
O9 Lieutenant General Lieutenant General Vice Admiral Lieutenant General
O10 General General Admiral General
O11 General of the Army   Fleet Admiral General of the Air Force

 

Rank -- Warrant Officer
Army Marine Corps Navy
Master Warrant Officer MW-4 Chief Warrant Officer W-4

Master Warrant Officer MW-4

 Chief Warrant Officer W-4
Chief Warrant Officer W-3 Chief Warrant Officer W-3
Chief Warrant Officer W-2 Chief Warrant Officer W-3 Chief Warrant Officer W-2
Warrant Officer W-1 Chief Warrant Officer W-2  

 

Rank -- Enlisted Personnel
Grade Army Marine Corps Navy Air Force
E1 Private E-1 Private Seaman Recruit Airman basic
E2 Private E-2 Private First Class Seaman Apprentice Airman
E3 Private First Class Lance Corporal Seaman Airman First Class
E4 Corporal / Specialist Corporal Petty Officer Third Class Senior Airman
E5 Sergeant Sergeant Petty Officer Second Class Staff Sergeant
E6 Staff Sergeant Staff Sergeant Petty Officer Third Class Technical Sergeant
E7 Sergeant First Class Gunnery Sergeant Chief Petty Officer Master Sergeant
E8 Master Sergeant Master Sergeant Senior Chief Petty Officer Senior Master Sergeant
E9 Sergeant Major / Command Sergeant Major Sergeant Major / Master Gunnery Sergeant  Fleet/Command Master Chief Petty Officer / Master Chief Petty Officer Chief Master Sergeant
E10 Sergeant Major of the Army Sergeant Major of the Marine Corps Master Chief Petty Officer of the Navy Chief Master Sergeant of the Air Force

Please keep in mind that the ranks listed above are current; the rank structure in place during the Korean War may differ slightly!