An angle measuring gauge incorporates four arms pivotally connected to form a quadrilateral. The arms are connected to a guide bar that attaches to the quadrilateral along a diagonal and forms an axis of symmetry. A first corner of the quadrilateral is pivotally attached to the guide bar and the opposite corner of the quadrilateral is pivotally connected and is slidable along the guide bar to adjust the angles of the quadrilateral. In practice, the first corner of the quadrilateral is adjusted to conform to a desired angle, and the guide bar bisects the angle formed by the first corner and can be used to either ride in a miter slot of a cutting tool, or adjust a miter gauge of a cutting tool to cut accurate miters.