The flag of Singapore has a horizontal bicolour design with two equal stripes. The top stripe is red (#ED2939) and the bottom stripe is white (#FFFFFF). In the upper left corner, there is a white crescent moon and five white stars forming a circle.

The aspect ratio of the flag is 2:3, meaning its width is 2 units and its height is 3 units. The crescent moon and the stars are located in a canton that spans the top left quarter of the flag, with a height equal to half the flag's height and a width equal to half the flag's width.

The crescent moon is stylized, with an outer diameter of 0.8 units and an inner diameter of 0.66 units. The circle formed by the five-pointed stars has a diameter of 0.6 units. Each star has a diameter of 0.1 units, and they are equally spaced around the circle. The distance between the center of the circle and the center of each star is 0.3 units.