Accurate Inside Measurements
A combination square will get you the precision you need
Using a measuring tape alone does not yield the precise inside measurements finish carpenters must have. Fine Homebuilding reader Phillip Zimmerman from Berkeley, California, created a solution to that problem by using both his measuring tape and a combination square. The square’s blade butts against the inside surface, while the tape measure records the distance from the opposite edge to the blade, thus eliminating any guesswork.