Electrical & Electronics

Cable Voltage Drop

Estimate voltage drop in copper or aluminium conductors.

CALCULATOR

Enter values

SystemConductorVoltage

V

Current

A

One-way length

m

Cable cross-section

USAGE

How to use it

Select system and conductor material.
Enter one-way length, current and cross-section.
Evaluate drop percentage against supply voltage.

FORMULA

Calculation

DC/1φ: ΔV = 2ρLI/A; 3φ estimate: ΔV = √3ρLI/A

Example

12 V, 10 A, 10 m, 2.5 mm² copper is about 1.38 V

TECHNICAL

Technical notes

This simplified estimate excludes temperature and reactance effects.
Use applicable codes and a qualified professional for installation decisions.