A system and method of designing the physical shape of and determining the electromagnetic characteristics of a bondwire in an electrical circuit, comprising the steps of enabling a user to define the position of the bondwire in the electrical circuit layout, defining the position and loop shape of the bondwire in a 3D representation of the electrical circuit, segmenting the bondwire into discrete segments, determining the electromagnetic characteristics of each of the bondwire segments thereby to determine the overall electromagnetic characteristics of the bondwire.