The flag of San Marino consists of two horizontal bands of equal size. The top band is white (color code: #FFFFFF) and the bottom band is light blue (color code: #5EB6E4). The aspect ratio of the flag is 3:4.

In the top-left corner, there is the coat of arms of San Marino, which is surrounded by a golden-yellow border (color code: #FFCD00). The coat of arms is centered vertically within the white stripe, with its base at approximately 1/8th of the flag's length from the hoist side.

The coat of arms features a shield with three towers on three peaks, each with a silver outline, and is adorned with a crown on top. Below the shield, there is a scroll with the Latin inscription "LIBERTAS."