The flag of Sint Maarten has an aspect ratio of 2:3. It consists of three horizontal stripes with the following color codes and proportions:

1. Top stripe: Red (#D21034), occupying 2/5 of the flag's height.
2. Middle stripe: White (#FFFFFF), occupying 1/5 of the flag's height.
3. Bottom stripe: Blue (#002B7F), occupying 2/5 of the flag's height.

On the left side of the white stripe, there is a coat of arms centered vertically. The coat of arms has a height equal to 4/5 of the white stripe's height.