Abstract: An adjustable window insulated covering for substantially reducing a user's heating and cooling bills. The adjustable window insulated covering includes at least one curtain member having a first layer made of foil material, a second layer made of plastic, and an intermediate layer made of insulating material; and also includes fastening members for fastening the side ends of the at least one curtain member to a window frame. As a first embodiment, the at least one curtain member includes a first and second curtain members which are movably mounted in upper and lower track members which are mounted to the window frame. As a second embodiment, the at least one curtain member is one curtain member which is carried by a roller member which is mounted in a housing which is securely mounted to a top of the window frame. As a third embodiment, the at least one curtain member is one curtain member which is detachably fastened to the window frame over the window with hook and loop fasteners.