Abstract: A system an method for determining the Dose Area Product (DAP) in an X-ray imaging system is provided. The present system constructs a pre-determined parameter space describing the DAP contour over ranges of typical imaging parameters. Later, when the employed in clinical imaging, a DAP processor on board the imaging system received a set of the imaging parameters being employed. The DAP applies the set of parameters to the parameter space to interpolate the DAP being delivered by the clinical imaging system. The present system may be individually calibrated to a specific X-ray imaging system to provide more optimal DAP values. Additionally, in imaging system employing an asymmetric shutter, such as a one-leaf shutter, the present system may determine a rotational scale factor for the DAP based on the rotation of the shutter. The rotational scale factor may also be calibrated to an individual X-ray imaging system.