A coarse-grained effective segment description of polymer solutions is presented, based on soft, transferable effective interactions between bonded and nonbonded effective segments. The number of segments is chosen such that the segment density does not exceed their overlap threshold, allowing polymer concentrations to be explored deep into the semidilute regime. This quantitative effective segment description is shown to preserve known scaling laws of polymer solutions and provides accurate estimates of amplitudes, while leading to a orders-of-magnitude increase in the simulation efficiency and allowing analytic calculations of structural and thermodynamic properties.