A study was conducted to numerically determine heat distribution and castability simulations of as cast magnesium-aluminum (Mg-Al) alloys. As cast alloys were undertaken and the resultant microstructures were simulated and compared with the experimental output. The temperature and the heat dissipation during casting was also simulated and compared with investigations for different geometries. Experimental and simulated evaluation was performed of the mold filling ability of all binary Mg-Al alloys containing up to 12% aluminum at various pressure heads and superheats. The alloys were cast in cylindrical chills, producing castings with 17 mm diameter and 160 mm length. The samples were prepared for light microscopy, interference layer microscopy, and scanning electron microscopy after casting. All castings were subjected to a melting temperature of 100 °C above liquidus of the alloy and cylindrical specimens for differential thermal analysis (DTA) were taken from the casting billet.