Starfleet Rank Index/Marines
Marshal & General Ranks
Field Marshal
The higest attainable rank in the Starfleet Marine Corps, Field Marshal is roughly equivalent to the rank of Fleet Admiral.
General
General is roughly equivalent to Starfleet's rank of Admiral.
Lieutenant General
Lieutenant General is roughly equivalent to Starfleet's rank of Vice Admiral.
Major General
Major General is akin to either Rear Admiral or Commodore (sometimes called "Rear Admiral, Lower Half") in Starfleet.
Brigadier General
Brigadier General is roughly equivalent to the rank of Fleet Captain.
Commissioned Marine Ranks
Brigadier
A Brigadier is roughly equivalent to the rank of Fleet Captain.
Colonel
A Colonel is equal to a Starfleet Captain in rank.
Lieutenant Colonel
A Lieutenant Colonel is comparable to a Commander in Starfleet.
Major
A Marine Major is equal to a Starfleet Lieutenant Commander.
Captain
A Marine Captain is equal in rank to a Starfleet Lieutenant.
First Lieutenant
File:M02-1Lt-Green.png First Lieutenant is roughly equivalent to the rank of Lieutenant Junior Grade in Starfleet's naval rank system.
Second Lieutenant
Second Lieutenant is SFMC's equivalent of the rank of Ensign.
Warrant Officer Marine Ranks
With regards to equivalent Starfleet Naval ranks, Warrant Officers are among the most self-explanatory. The only difference is the use of classes instead of grades when one reaches the rank of Chief Warrant Officer (CWO).
Chief Warrant Officer, First Class
Chief Warrant Officer, Second Class
Chief Warrant Officer, Third Class
Warrant Officer
Enlisted Marine Ranks
Sergeant Major
The highest of the enlisted ranks, Sergeant Major is equal to Master Chief Petty Officer.
Master Sergeant
Master Sergeant is roughly equivalent to Senior Chief Petty Officer in Starfleet's Navy.
Gunnery Sergeant
Gunnery Sergenat is the same rank as Chief Petty Officer on a starship.
Staff Sergeant
Staff Sergeant is equal to Petty Officer 1st Class.
Sergeant
Marine Sergeant is approximately the same rank as Petty Officer 2nd Class.
Corporal
Corporal is equal to Petty Officer 3rd Class in Starfleet's Naval ranks.
Lance Corporal
A Lance Corporal is approximately equal in rank to a Crewman 1st Class in Starfleet.
Private, First Class
Private 1st Class is roughly equivalent to Crewman 2nd Class in Starfleet.
Private
Private is the lowest enlisted rank in the SFMC. It's equal to Crewman 3rd Class.