Live tool/tool/wire-voltage-drop-calculator

Wire Voltage Drop Calculator

Estimate circuit voltage drop from conductor size, current, run length, and system voltage.

EngineeringElectricalReference

Current

One-way length

System voltage

Copper conductor size

Voltage drop

4.32 V

Drop percent

3.6%

Load voltage

115.68 V

Circuit resistance

0.27 ohm

Voltage-drop warning

This exceeds the common 3% branch-circuit rule of thumb. Consider a shorter run, lower current, or larger conductor.