A method is utilized to calculate a boundary leakage in a semiconductor device. A boundary is detected between a first cell and a second cell, which the first cell and the second cell are abutted to each other around the boundary. Attributes associated with cell edges of the first cell and the second cell are identified. A cell abutment case is identified based on the attributes associated with the cell edges of the first cell and the second cell. An expected boundary leakage between the first cell and the second cell is calculated based on leakage current values associated with the cell abutment case and leakage probabilities associated with the cell abutment case.