Wire Size Calculator

Calculate the proper wire gauge (AWG) for electrical circuits based on current load, voltage drop requirements, and NEC ampacity ratings.

Load Current (A)

System Voltage (V)

One-way Distance (ft)

Max Voltage Drop (%)

Conductor Material

Conduit Fill

About Wire Sizing

Proper wire sizing is critical for electrical safety and code compliance. Wire must be sized to handle the load current safely and limit voltage drop to acceptable levels.

Key Factors:

Ampacity: Wire's current-carrying capacity
Voltage Drop: Voltage loss due to wire resistance
Temperature: Higher temperatures reduce ampacity
Conduit Fill: Multiple wires require derating

NEC Requirements:

Wire ampacity must exceed load current
Voltage drop should not exceed 3% for branch circuits
Combined feeder and branch circuit drop: max 5%
Overcurrent protection required