voltage drop calculator in DC or AC circuit

This value only used for adjusting conductor resistance.

Length of cable in feet (one-way distance)

Load current in amperes


Estimated voltage drop

Select the material either copper or aluminum, the size of the conductor, the voltage and phase from a list of common voltages, then enter the one way circuit length in feet, and load in amperes..

Online voltage drop calculator in DC or AC circuit:

Use this calculator to estimate cable voltage drop for sizing conductors.

Voltage drop is the decrease of electrical potential along the path of a current flowing in an electrical circuit. Voltage drops in the internal resistance of the source, across conductors, across contacts, and across connectors are undesirable because some of the energy supplied is dissipated. The voltage drop across the electrical load is proportional to the power available to be converted in that load to some other useful form of energy. For example, an electric space heater may have a resistance of ten ohms, and the wires that supply it may have a resistance of 0.2 ohms, about 2% of the total circuit resistance. This means that approximately 2% of the supplied voltage is lost in the wire itself. An excessive voltage drop may result in the unsatisfactory performance of a space heater and overheating of the wires and connections.