Quantifying total well loss through well screens has been traditionally undertaken through experimentally based empirical equations or equations derived for water flow through (circular) orifices. Advances in computer capacity enables incorporation of CFD formulations at millimeter scale, coupling Darcy flow and Reynolds Averaged Navier Stokes (RANS) to better understand and quantify processes related to well loss for different screen types. This study provides a methodology of quantifying well screen head loss using numerical models, coupling Darcy flow (aquifer and filter/gravel pack) with turbulent flow (in‐well and through screen) at a sub‐millimeter scale. Results are used to compare performance of four different types of well screens (Louver, slotted, bridge and wire wrap) and their overall impact and contribution to total well head loss for different slot apertures, pumping rates and hydraulic conductivity of the filter/gravel pack providing a new empirical formulation to quantify screen head loss.