Wire Gauge Calculator – Calculate Required Wire Size
Determine the appropriate wire gauge for your electrical project. Our calculator considers current, length, voltage, and acceptable voltage drop to recommend the right AWG size.
Recommended: 3% for branch circuits, 5% total
How to Calculate Wire Gauge
Enter Current & Length
Input the current (amps) and wire run length for your circuit.
Set Voltage & Drop Limit
Enter system voltage and maximum acceptable voltage drop percentage.
Get Recommended AWG
See the recommended wire gauge with actual voltage drop results.
Key Features of This Wire Gauge Calculator
**AWG Selection**
Recommends proper American Wire Gauge from 14 AWG to 4/0 AWG.
**Material Options**
Support for both copper and aluminum wire calculations.
**Voltage Drop Analysis**
Calculates actual voltage drop to ensure code compliance.
**NEC Guidelines**
Uses standard 3% voltage drop recommendation for branch circuits.
Frequently Asked Questions
What wire gauge do I need?
Wire gauge depends on current, length, and voltage. Higher current and longer runs need thicker wire (lower AWG number). This calculator determines the proper size for your application.
What is voltage drop?
Voltage drop is the reduction in voltage as electricity travels through wire. NEC recommends max 3% drop for branch circuits, 5% total from service to load.
Copper vs aluminum wire?
Copper conducts better and is more durable but costs more. Aluminum is cheaper but needs larger gauge for same current. Aluminum requires special connectors and anti-oxidant paste.
What does AWG mean?
AWG (American Wire Gauge) is the standard wire sizing system. Counterintuitively, smaller numbers = thicker wire. 14 AWG is thinner than 10 AWG. 0000 (4/0) is very thick.
Why does wire length matter?
Longer wires have more resistance, causing more voltage drop and heat. Double the length = double the resistance. Long runs need thicker wire to compensate.
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