A saw guide device for the rapid and precise cutting of perpendicular notches in framing lumber using a portable circular saw. The device consists of an edge-of-board follower rail, a support arm, and a pivotally adjustable saw fence. Externally affixed to the saw fence are a horizontal cut locator arm and a saw stop tab. The locator arm has a cut alignment tang and a saw blade recess slot. The saw stop tab has a thumbscrew adjuster. The device is positioned by the alignment tang, which drops into a previous cut. During operation the saw foot overruns the cut locator arm and is stopped by the tab. Thumbscrew adjusters are located at each end of the follower rail to allow for variation in depth of the perpendicular notch. Various angular scales are marked on the upper surface of the follower rail to aid in saw fence setup.