Loose-snow avalanches occur frequently after snow-falls or as long as snowpack evolves in winter.The two relevant points in the signature of this kind of avalanches are: the lack of internal cohesion and the inverted V shape of the avalanche, also known as ‘'pear'' shape. In this research paper, the opening angle of such snow avalanches is investigated. A discrete mechanical model is defined and Mohr-Coulomb yield criterion is considered. Thanks to a graphical solution that considers Mohr's circles, the opening angle is found and its independence from the value of the cohesion is shown