A tool and method for locating a proper position for a portal incision for hip arthroplasty, the tool having at least one generally straight body defining an axis, the generally straight body having a slot at one end, the slot being angled at an approximately 45 degree angle relative to the axis of the generally straight body, the slot configured to receive a cutting member or guide tool. A second generally straight body may be connected to the first generally straight body to form a right angle. If the lengths of the two generally straight bodies are substantially equivalent, then when the second generally straight body is inserted into the acetabulum, the first generally straight body positions the slot in the proper location such that sliding a guide tool or cutting member through the slot allows a portal incision to be created in the proper location. In some embodiments, the generally straight bodies may have adjustable lengths.