If you have a protractor with inner and outer alignment guides, and IF your cartridge cantilever is aligned at both points, then your overhang is correct. if not, then slide your cartridge forward or back until it is aligned at both points without readjustment. Otherwise you can just use a mm ruler and measure from the tonearm pivot to the TT spindle, and then from the pivot to the stylus, and subtract. Start by doing this anyway, but the test is to be aligned at both points. Sometimes the tonearm is not actually installed precisely.
