Our computational model achieves quantitative agreement with experimental surface pressure-area isotherms at 293 K, successfully reproducing key features including the lift-off area, phase transition plateau, and collapse pressure within experimental uncertainty. This is significant, as both experimental and computational approaches have inherent limitations. Given that experimental data in the literature span a range of values, achieving quantitative agreement within experimental uncertainties is desirable. In a field where most computational approaches fail to reproduce DPPC pressure-area isotherms at different temperatures even qualitatively, our approach provides a robust model that captures pressure-area isotherms within the experimental data range, with transferable parameters across temperatures. The quantitative accuracy of the DPPC model is reinforced by its ability to reproduce temperature-dependent phase behaviors and structural characteristics of the DPPC bilayer. Our model can be readily extended to monolayers containing other phospholipids and cholesterol. Future work will explore mixed monolayers and the effects of nanoparticles. This work was supported by the National Science Foundation CBET grant # 2040302 and DMR grant #2138052.