Using a ruler or tape measure to set the depth of cut on a tablesaw or router table often proves inaccurate. Isn't there a better way to make these measurements, short of buying a special tool?

Turn your combination square into an accurate depth gauge with two small pieces of wood, a thumbscrew, and a threaded insert. First, cut a 34 "-thick block of hardwood about 3" long, and cut a kerf down the middle just wide enough to fit over the edge of the blade on your square. Then, saw out the notch in the lower half of the block to fit around the head of the square.

Glue a piece of 18 "-thick hardwood to the bottom, as shown above. With epoxy, secure a threaded insert into the upper half of the block, put in a thumbscrew, and you're ready to quickly gauge the blade height.
—Mark Albrecht, Houston, Texas