Australia’s 1:2 flag places the Union Jack in the canton, a seven-pointed Commonwealth Star below it, and five stars of the Southern Cross across the fly.
Specification
The flag is twice as long as it is high. The Union Jack occupies the upper hoist quarter. A large seven-pointed Commonwealth Star is centered in the lower hoist quarter; the fly carries four seven-pointed stars and one smaller five-pointed star forming the Southern Cross.
Official color references
PANTONE 280 / official referencePANTONE 185 / official referenceUnprinted field and starsConstruction notes
Schedule 1 fixes each star’s center and diameter relative to the fly. The Commonwealth Star’s outer diameter is three tenths of the flag’s hoist. Four Southern Cross stars have seven points and an outer diameter of one seventh of the fly; the smaller Epsilon Crucis has five points and an outer diameter of one twelfth.
Historical record
The winning design from a national competition was first flown on 3 September 1901. Five entrants—Annie Dorrington, Ivor Evans, Leslie Hawkins, Egbert Nuttall, and William Stevens—were declared joint winners. The Commonwealth Star gained a seventh point in 1908, and the Flags Act 1953 established the blue flag as the Australian National Flag.
Source trail
Australian Government: Australian National Flag elements and history ↗
Department of the Prime Minister and Cabinet: Australian Flags construction sheet ↗