A voltage gradient or, more accurately, potential gradient, is the change in electric potential measured between a point of high potential and a point of low potential. It is normally measured with respect to one or other of these two points.

A practical example of a potential gradient can be demonstrated by connecting a variable resistor as a potentiometer. If an external voltage is applied across opposite ends of the potentiometer, then a potential gradient can be observed by connecting a voltmeter between one end of the potentiometer and its wiper terminal, and varying the position of the wiper. As the wiper is moved from one end of the potentiometer to the other, the potential will be seen to fall towards zero.