Rules for Mortise and Tenon Joinery

George Vondriska teaches you how to calculate the correct dimensions for mortise and tenon joinery so you can ensure that the pieces will fit together properly for your woodworking projects. He discusses measuring for the cut size based on the dimensions of the rail, and recommends of course rounding the cut size to the closest cutter that you have. So: first do the math, then cut the mortise, and finally make the tenon to match it.