Australian Flags come in many sizes.
300 x 200mm hand waver
450 x 300mm hand waver
600 x 300mm (2ft) is the size flown on boats up to 10 mtrs in length and also used as a Courtesy Flag on boats when visiting other countries.
900 x 450mm (1yd) is the size flown on boats between 10 and 14 mtrs
1350 x 675mm (1.5yd)
1500 x 900mm (1.8yd) a little smaller than the 'standard flag pole flag'
1800 x 900mm (2yd) is standard flag size for a 6mtr flag pole at homes and schools