The flag of Réunion is a rectangular shape with a ratio of 2:3. It consists of two equal horizontal bands: one white and one red. The white band is positioned on top and the red band on the bottom.

The colors of the flag are defined as follows:

• White (Pantone 279 C, RGB 255/255/255)
• Red (Pantone 186 C, RGB 255/0/0)

There are no specific geometric properties or measurements related to the flag's design beyond the standard 2:3 aspect ratio.