The flag of San Marino consists of two equal horizontal bands of white (top) and light blue (bottom) with the national coat of arms superimposed in the center. The coat of arms depicts a shield surrounded by oak and laurel leaves, with a crown on top and a scroll below bearing the word "LIBERTAS" (Latin for "liberty").

The aspect ratio of the flag is 3:4, and the geometric properties are rectangular with a length of 120 units and a width of 90 units. The RGB color codes for the white and blue colors are #FFFFFF and #6BAED6, respectively.

Note that although the coat of arms is an important part of the flag's design, it is not considered one of its geometric properties or measurements.