Fluid flow across porous screens has been the subject of extensive research mainly because of its multitude applications ranging from traditional uses in fishing and agriculture to more sophisticated engineering in industrial settings, medical and health care applications. Face masks are a prime example of porous screens being used in healthcare applications. Research on face masks have, however, focused mainly on the efficacy of such masks to stop droplet transmission. Only a handful of studies have been carried out on understanding the flow characteristics of such face masks. This study attempts to bridge this gap by characterising fluid flow across such porous screens by computationally determining the pressure drop during air flow across the screens. The analysis is carried out using the computational platform ANSYS FLUENT. Different configurations of the porous screens - single and double-layered - are adopted for studying the pressure drop characteristics. In addition, the effect of various pertinent parameters such as the flow velocity, pore size, thickness of the screen layers and spacing between the layers, are also studied.