The interest of 2D materials is constantly increasing because of their very attractive mechanical, electrical and optical parameters. They have been used in many applications, e.g. photodetectors, sensors, modulators, insulators. One of the recently discovered 2D materials is phosphorene. In contrast to graphene, phosphorene has a direct bandgap tuned by numbers of layers in the 2D structure. The phosphorene flakes are strongly anisotropic. This study presents the detailed optical properties of electrochemically obtained phosphorene flakes versus centrifugation speed. A layer of phosphorene on a silicon wafer changes with increased centrifuge speed. A relationship that combines the size of the phosphorene flakes and ellipsometric angles, as well as the transmittance data obtained on a spectrophotometer was received. Hence, such an approach could allow for non-contact comparing the size of phosphorene flakes.