The flag of Saint Barthélemy consists of a white field with the coat of arms of the island in the center. The coat of arms features a Maltese cross with stylized suns in each quadrant and crowned by a three-towered castle, which is topped with a gold fleur-de-lis. The flag has an aspect ratio of 2:3, and the coat of arms has a height-to-width ratio of 8:7. The colors used in the flag are:

• White: #FFFFFF
• Blue: #0055A4
• Red: #EF4135
• Yellow: #FCD116

There are no specific measurements for the geometric properties of the coat of arms, but it is centered on the flag with equal amounts of white space around all sides.