Brain tumor, a notorious disease, has affected and devastated many lives. This disease has been the centre of attention of thousands of researchers for many decades, around the world. Researchers have combined their knowledge and efforts from many areas ranging from medical to mathematical sciences, to better understand the disease and to find more effective treatments. The key objective of this paper is to form a methodology to detect & extraction of brain tumor from a patient’s MRI. This method incorporates with some noise removal functions, segmentation and morphological operations which are the basic concepts of image processing. Proposed methodology will detect tumor and finally the fractional area of tumor will be calculated. All of this processing will be done by MATLAB software.