The flag of Sint Maarten is composed of a horizontal tricolor with the following color codes:

1. Top stripe: red (#d21034)
2. Middle stripe: white (#ffffff)
3. Bottom stripe: blue (#002b7f)

On the left side of the flag, there is an emblem within a red-bordered vertical white triangle. The triangle has its base on the hoist side and its height equal to the width of the flag.

The aspect ratio of the flag is 2:3, meaning it is twice as long as it is tall. Exact geometric properties and measurements may differ depending on the specific flag size being used.