Monolithic two-terminal (2T) perovskite/silicon tandem solar cells arerapidly progressing toward higher power conversion efficiencies (PCEs), which hasled to a prominent role for this technology within the photovoltaics (PV) researchcommunity and, increasingly, in industrial PV R&D. Here, we define a practical PCEtarget of 37.8% for 2T perovskite/silicon tandems based on metrics derived fromstate-of-the-art silicon and perovskite solar cells and discuss possible pathways towardthat goal. It is hoped that this PCE target will serve to guide future researchdirections, most notably into continued improvements in the radiative efficiency ofthe mixed-halide perovskite top cell via bulk and surface passivation strategies.