The flag of Sint Maarten has a blue, white, and red background divided diagonally from top left to bottom right. The blue triangle occupies the hoist side, while the red triangle is on the fly side. In the center of the flag, there is a larger white five-pointed star with smaller white stars on either side of it.

The official color codes for the flag are Pantone 032C for red, Pantone 286C for blue, and Pantone White for white. The aspect ratio of the flag is 2:3, and its geometric properties include a diagonal division, three triangles, and three stars.

The measurements of the flag vary depending on its size, but the width should be twice the height. For example, a 2 feet by 3 feet flag would have dimensions of 24 inches by 36 inches.