A microwave heating apparatus includes a cavity arranged to receive a load. At least one microwave generator is configured to feed a plurality of microwaves into the cavity. At least one image-capturing device and a control unit is adapted to obtain load volume information of the load within the cavity based on information recorded by the image-capturing device about at least one portion of the load, obtain load density information using at least one of a user input and information recorded by the image-capturing device about at least one portion of the load, determine load mass information based upon the load volume information and the load density information, determine a heating pattern based upon the load mass information and control the at least one microwave generator to provide the heating pattern within the cavity.