Abstract: A combination square includes a blade, a body, and a lock. The body comprises a slot adapted to receive the blade therein and permit sliding translation of the blade parallel to the longitudinal axis of the blade, allowing the position of the blade to be adjusted relative to the body. The lock is adapted to lock the position of the blade relative to the body in a locked configuration and to allow adjustment of the position of the blade relative to the body in a released configuration. The combination square also comprises a removable extension bracket being wider than and removable from the body and comprising one or more working surfaces.