Calculate system voltage drops safely. Optimize circuit performance today.
The voltage drop calculation relies on standard electrical engineering principles:
$$VD = \frac{K \times L \times I \times R}{1000}$$
Where $K$ is the phase multiplier (2 for single phase, $\sqrt{3}$ for three phase), $L$ is the one-way distance in feet, $I$ is the load current in amperes, and $R$ is the effective AC resistance per 1000 feet.
Voltage drop is a natural phenomenon that occurs in all electrical circuits due to the inherent resistance found within conductors. As electrical current travels from the source to the connected load, energy is dissipated in the form of heat. This reduction in voltage can cause downstream equipment to function inefficiently, overheat, or fail prematurely. Managing voltage drop is a vital task for electrical contractors, engineers, and technicians working on residential, commercial, or industrial wiring architectures.
National electrical safety codes, such as the NEC, strongly recommend limiting total voltage drop across both feeders and branch circuits to a maximum threshold of 5 percent, with no more than 3 percent on branch circuits alone. Keeping voltage levels stable guarantees that motors run at proper torques, lighting systems maintain full luminescence, and sensitive electronics avoid performance throttling or hardware degradation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.