Voltage Drop

Estimate two-way resistive voltage drop along a conductor run.

How this calculator works

Enter the values for first value, second value and review the units before calculating.

Formula / method

Voltage drop = current × (2 × length × resistance per meter)

Worked example

10 A through a 20 m run at 0.001 Ω/m drops 0.4 V round trip.

Assumptions and limitations

The supplied resistance is per meter and the return path has the same length and resistance.

Temperature, connectors, AC reactance and installation code are not included.