The flag of Guam has a dark blue base with a narrow red border on all sides. In the center, there is a circle consisting of a red outline and a light blue inside. Within the circle, there is a brown proa, a traditional sailing canoe native to the island, positioned diagonally. The proa is surrounded by a white five-pointed star on each side.

The aspect ratio of the flag of Guam is 22:41, and the geometric properties include a rectangular shape with a length of 41 units and a width of 22 units. The color codes for the flag are as follows:

• Dark Blue: Pantone 286 C / RGB (0, 46, 104)
• Red: Pantone 186 C / RGB (206, 17, 38)
• Light Blue: Pantone 298 C / RGB (120, 182, 219)
• Brown: Pantone 469 C / RGB (74, 47, 39)
• White: Pantone White / RGB (255, 255, 255)