Broadly speaking the present invention is directed to a system for calculating a volume of fluid that is disposed within a container. The system includes (1) an imaging device that captures and stores an image of at least the volume of fluid in the container; (2) a background disposed behind the container so that at least the volume of fluid in the container is disposed in front of the background; and (3) a processor that performs at least one operation on the stored image to calculate the volume of the fluid within the container.