Convertible garment (1; 1') configured to cover at least part of a user's body and comprising: - a shaped rear sheet and a shaped front sheet superimposable onto one another to define a configuration of the garment (1; 1 ') and each delimited by a lower edge (2b, 3b), by an upper edge (2a, 3a) and by two lateral edges (2c, 2c) interposed between the lower edge (2b, 3b) and the upper edge (2a, 3a); - a belt element carried by one of said rear sheet and front sheet and configured to gird a portion of the user's body; - first fastening elements carried by the belt element; and - second fastening elements carried by the other of said rear sheet and front sheet and couplable with the first fastening elements to determine a superimposition position between end lateral portions of the rear sheet and corresponding end lateral portions of the front sheet, each carrying one respective said lateral edge (2c, 3c); wherein the superimposed end lateral portions (2d, 3d) define respective lateral openings of said garment (1; 1'); and wherein, at least in a closing condition of said belt element, said superimposed end lateral portions (2d, 3d) are decoupled from one another so as to delimit said lateral openings along a longitudinal direction of said garment (1; 1'); characterized in that the convertible garment comprises third fastening elements carried by said belt element; said second fastening elements being selectively couplable with the first fastening elements or with the third fastening elements to determine two different superimposition positions of said end lateral portions (2d, 3d) defining, respectively, two configurations of said garment (1; 1') different from one another. - a shaped rear sheet and a shaped front sheet superimposable onto one another to define a configuration of the garment (1; 1 ') and each delimited by a lower edge (2b, 3b), by an upper edge (2a, 3a) and by two lateral edges (2c, 2c) interposed between the lower edge (2b, 3b) and the upper edge (2a, 3a); - a belt element carried by one of said rear sheet and front sheet and configured to gird a portion of the user's body; - first fastening elements carried by the belt element; and - second fastening elements carried by the other of said rear sheet and front sheet and couplable with the first fastening elements to determine a superimposition position between end lateral portions of the rear sheet and corresponding end lateral portions of the front sheet, each carrying one respective said lateral edge (2c, 3c); wherein the superimposed end lateral portions (2d, 3d) define respective lateral openings of said garment (1; 1'); and wherein, at least in a closing condition of said belt element, said superimposed end lateral portions (2d, 3d) are decoupled from one another so as to delimit said lateral openings along a longitudinal direction of said garment (1; 1'); characterized in that the convertible garment comprises third fastening elements carried by said belt element; said second fastening elements being selectively couplable with the first fastening elements or with the third fastening elements to determine two different superimposition positions of said end lateral portions (2d, 3d) defining, respectively, two configurations of said garment (1; 1') different from one another.