Sheet metal forming is a huge market with a major share going to the consumer and automobile sector. Sheet metal is normally formed and only then piercings if any are done. These piercings if on a complicated form are very difficult to perform and very expensive tooling with cams are needed. This study aims at studying the forming limit of different perforation sizes (diameter 6, 8 &10), open area % (5, 10 & 15) and ligament ratios (0.3, 0.4 & 0.5) on 1.0 mm commercially pure Aluminium sheet metal. The standard Limiting height dome test was used to determine the limiting dome height before the onset of the crack and the corresponding limiting minor and major strains and limiting minor and major stresses were found.