The use of inorganic matrices in structural engineering field has increased considerably thanks to novel retrofitting systems which focus on the best symbiotic action between fiber-based mesh embedded into mortar (lime- or cement-based). The possible combinations of the constituents are so many, but a clear distinction can be made concerning the type of reinforcement: fiber mesh or FRP-grid. In the first case, a Fabric Reinforced Cementitious Matrix/Mortar (FRCM) is obtained; the latter is a Composite Reinforced Mortar (CRM). One of the most adopted applications is the shear strengthening of masonry walls. In fact, FRCM/CRM provides its own additional in-plane strength and, at the same time, improves the original capacity of the wall itself. This double-action behavior is demonstrated in numerous experimental tests evidencing the influence of fabrics and mortars when combined to several masonry typologies. It must be highlighted that state-of-knowledge is currently more consolidated for FRCM systems, for which Design-Oriented Models (DOMs) have been calibrated with respect to large databases. Conversely, further research efforts are needed referring to CRM-systems. With this aim, the present paper reports on the updated data availability concerning the shear strengthening of masonry walls with CRMs (as part of a larger study). The goal is to propose a new empirical formula for design purposes using the best fit method, while minimum scatter between the experimental and theoretical outcomes.