Re^3TM Voltage Drop Calculator

Mode Residential Commercial 60°C Commercial 75°C Commercial 90°C

Current AC DC

Units for Length of Cable Run Feet Meters

Phase Single

Conductor Copper Aluminum

Installation Cable, Conduit (non-Steel), & Direct Burial

Residential
Designed to be used by homeowners and provides an increased safety factor. Limited to single phase circuits with maximum cable temperature of 60°C for circuits under 100 Amps and does not allow parallels. Also limits installation types to cable, non-ferrous conduits (PVC for example), or direct burial.

Commercial 60° C
For electrical professionals. Allows all options to be modified. Uses 60°C ampacities from the NEC.

Commercial 75° C
For electrical professionals. Allows all options to be modified. Uses 75°C ampacities from the NEC.

Commercial 90° C
For electrical professionals. Allows all options to be modified. Uses 90°C ampacities from the NEC.

The power factor for the calculation must be between 0 and 1.

Calculator Minimum Conductor Size Maximum Circuit Distance Voltage Drop

Length of cable run (feet)

Voltage (volts)

Max Voltage Drop (%)

Current at end of cable run (amps)

Minimum Conductor Size
Calculates the minimum conductor size for a given circuit distance, current load, voltage, and voltage drop.

Maximum Circuit Distance
Calculates the maximum circuit distance for a given conductor size, current load, voltage, and voltage drop.

Voltage Drop
Calculates the voltage drop when the conductor size and circuit distance are already known.

Parallels are sets of conductors electrically joined at both ends. For example, 2 parallels would have 2 conductors per phase and 2 conductors per neutral - electrically joined at both ends.