The continuum phase field approach has become a method of choice to handle high volume fractions of diffusionally and elastically interacting precipitates of complicated shapes and spatial distributions. However, much previous work is limited to qualitative studies of prototype binary systems. Recently significant progress has been made in further development of the phase field method into a quantitative model for engineering applications. In this presentation, we review our recent efforts in developing the phase field method into a useful quantitative modeling tool for the prediction of g' precipitation in Ni-base superalloys by (1) extracting material parameters from experiment for model calibration and (2) linking the fundamental model inputs to CALPHAD thermodynamic database and DICTRA diffusivity database. Examples of the continuous cooling process and other current work will be discussed. The work is supported by the Air Force Research Laboratory and the National Science Foundation.