A circular saw guide is provided having an upper frame member with a plurality of angular indicia on an edge thereof. A lower frame member is pivotable relative to said the frame member. The upper surface of the lower frame member is adapted to receive a workpiece to be cut thereon. A pivot member is provided for selectively preventing or allowing pivoting of the lower frame member relative to the upper frame member. The upper surface of the upper frame member is adapted to guide the footplate of the circular saw. By pivoting the lower frame member relative to the upper frame member, the edge of the workpiece can be aligned with a desired indicia, which is indicative of the angle that the board will be cut. A method of cutting a workpiece at a desired angle is also disclosed.