The size of the star of the Chilean flag is defined by Law No. 2597 January 11, 1912 as «the diameter of the star will be half the side of the blue square [canton]». The same rule of the star size goes for the Presidential Flag.Apparently, it seems that the size and the exact positioning of the star is nowhere prescribed. My assumption that seems quite strightforward is that the star is inscribed in an imaginary circle centered in the blue square and having diameter half the length of the square size, i.e. 14 of the hoist.

Website: http://www.crwflags.com/fotw/flags/cl.html