The Division is set on the island of Manhattan in New York, but it's not a true 1:1 scale recreation, which makes it more difficult to work out exactly how big it is. YouTuber MarcoStyle did the math to determine the size of the map and how it compares to other open world maps.
He found that The Division's map is 2.8km (1.7 miles) in width, which he then went on to say will take just over 8 minutes to cross if there's nothing standing in your way. He charted Grand Theft Auto V's map with the same technique and found that The Division's map is slightly smaller than the city area of Los Santos. You won't have vehicles to traverse the world in The Division though, so you may be relieved that it's more condensed.
MarcoStyle then turned his attention to Fallout 4 and found that its map and The Division's are around the same size.
Ubisoft has said that there will be at least three DLC expansions released as part of the Season Pass, which could extend the scope of The Division's world.
You'll be able to explore The Division's Manhattan for yourself when the game drops on March 8th.