The flag of Latvia consists of three horizontal bands with the following colors and proportions:

1. Top band: Carmine red (#9E3039), occupying 2/5 of the flag's width.
2. Middle band: White (#FFFFFF), occupying 1/5 of the flag's width.
3. Bottom band: Carmine red (#9E3039), occupying 2/5 of the flag's width.

The aspect ratio of the flag is 1:2, meaning its width is twice its height. The geometric properties include three parallel, horizontal stripes with the top and bottom stripes being equal in size and the middle stripe being half their size.