When a bead shape is round or flat round, we will generally use one measurement in millimeters. Example a 4mm round bead is measured from bead hole to bead hole. When the bead shape is not round, but uniform in length and width, we will use two measurements. Example: 6x6mm square bead. Pendants are measured with the bail included unless it is loose and can be removed. Drops and links generally have two dimensions, with the largest dimension listed first. Example: 10x6mm link with two loops. This measurement will not include the loops. For chips, pebbles and nuggets, we refer to them as mini, small, medium, large, extra large or gigantic.