Spannungsabfall Rechner

Calculate voltage drop for electrical wiring

Inhaltsverzeichnis

Wie zu Verwenden

Enter the current in amperes
Enter the wire length in feet (one-way distance)
Select the wire gauge (AWG)
Click calculate to see voltage drop and percentage drop

What is Voltage Drop?

Voltage drop is the reduction in voltage that occurs as electrical current flows through a wire's resistance. Longer wires, smaller wire gauges, and higher currents all increase voltage drop.

Excessive voltage drop can cause equipment malfunction, reduced efficiency, and safety hazards. The National Electrical Code (NEC) recommends keeping voltage drop below 3% for branch circuits and 5% total.

Proper Wire Sizing

AWG (American Wire Gauge): Smaller numbers = larger wire
Larger wires have less resistance and voltage drop
Consider both current capacity and voltage drop
Long wire runs may require larger gauge than ampacity alone suggests

Applications

Electrical installation design
Wire gauge selection
Circuit troubleshooting
Solar panel installations
Low voltage lighting systems
Automotive wiring

Häufig gestellte Fragen

What is an acceptable voltage drop?: The NEC recommends maximum 3% voltage drop for branch circuits (outlets) and 5% total from service panel to outlet. For critical equipment, aim for even lower voltage drop.
How do I reduce voltage drop?: Use larger wire gauge (smaller AWG number), shorten wire length, or reduce current. For long runs, consider increasing wire size by one or two gauges.
Why does wire length matter?: Longer wires have more resistance. The calculator accounts for round-trip distance (current flows out and back), so actual resistance is twice the one-way length.