Various programming techniques are described for medical devices that deliver electrical stimulation therapy that may include mapping between discrete electrical stimulation parameters and a graphical view of the electrical stimulation representing a stimulation zone generated by the parameters. In one example, a method includes receiving, via a programmer for an electrical stimulator, user input that graphically manipulates at least one of size and a shape of a graphical representation of at least one electrical stimulation zone displayed on the programmer, and defining a program to control delivery of electrical stimulation therapy based on the user input.