Update currently measured at 4.8 GB.
New images and details for Grand Theft Auto Online’s Heists DLC dropped recently and while the content is scheduled to release on March 10th for current and next gen consoles, some users have reported receiving it earlier.
Right now, it seems 4.8 GB is the standard size for the update on PS4 and Xbox One. The Xbox 360 and PS3 updates apparently weigh in at 1.2 GB.
Five Heists are being provided as part of the DLC and four players will have to team up to complete them. It should be noted that other content including new free roam activities and PvP modes like Adversary. Heists for the PC version will go live as soon as the port is out on April 14th. Stay tuned for more details in the meantime.