Voltage Drop Calculator (NEC & CEC) | PipePal
Calculate voltage drop quickly and accurately for single-phase and three-phase systems using copper or aluminum conductors.
UNIT
—
—
—
CEC: 3% branch / 5% total | NEC: 3% branch / 5% feeder+branch
Calculation:
How Voltage Drop Works
Voltage drop occurs when electrical current travels through a conductor and loses voltage due to resistance in the wire. Longer distances and smaller wire sizes increase voltage drop. This calculator helps electricians determine the expected voltage loss and ensure circuits stay within recommended limits.
Voltage Drop Formula
Voltage drop can be calculated using the formula Vd = (2 × K × I × D) ÷ CM for single-phase circuits. In this equation, K represents conductor resistivity, I is the current in amperes, D is the distance in feet, and CM is the circular mil area of the conductor.
Voltage Drop Example
Example: A 120-volt circuit using 12 AWG copper wire carrying 20 amps over 100 feet will experience approximately X volts of drop. This calculator helps electricians quickly determine voltage loss and ensure circuits stay within recommended limits.