A sizing plate for sizing a native valve annulus in a patient's heart for either valve replacement or repair during a minimally invasive surgical procedure is shown and described. The sizing plate is generally shaped such that it corresponds to the shape of the native valve annulus. Additionally, a thickness of the sizing plate is such that it can be inserted through a space between the ribs of the patient during the procedure. The sizing plate includes two keyways extending though the plate separated by a bridge. The keyways are sized and shaped such that they are adapted to be engaged by a minimally invasive surgical tool such as a laparoscopic grasper. The keyways in conjunction with the bridge facilitate manipulation of the sizing plate by the grasper from an external location.
