An expandable sleeping bag or bunting bag includes features in which the size of the bag is adjustable to accommodate the growth of the child. To expand or contract the sleeping bag in width, one or more additional tapes of zipper teeth are sewn to the front of the garment adjacent to, and parallel to, the regular zipper. To expand or contract the sleeping bag in length, a pair of parallel zippers permits the removal or insertion of a length expansion strip extending around the circumference of the sleeping bag.