The flag of Antigua and Barbuda has an aspect ratio of 2:3. It consists of three main colors: red (#CE1126), white (#FFFFFF), and blue (#000080). The base color is red, featuring a horizontal white stripe (with its width being half the flag's width) and below it, a blue stripe (also half of the flag's width). A diagonal black stripe runs from the bottom left corner to the top right corner, with two thin white-bordered segments on either side.

The black stripe is approximately 1/8th of the flag's width, while each white border is half the width of the black stripe. Additionally, there's a yellow (#FCD116) seven-pointed sun symbol in the middle of the flag intersecting the stripes.

Note that the exact geometric properties and measurements of the flag may vary slightly depending on the source you consult.