Calculate the correct electrical wire size based on current load, distance, voltage drop, and ambient temperature. Ensure safe and efficient electrical installations.
Proper wire sizing is critical for electrical safety and efficiency. Our wire size calculator helps you determine the correct American Wire Gauge (AWG) size based on your specific electrical requirements, ensuring compliance with electrical codes and optimal performance.
The current load is the amount of electrical current that will flow through the wire, measured in amperes. This is determined by the electrical devices or equipment connected to the circuit. Always use the maximum expected current, including any future additions to the circuit.
The distance from the power source to the load affects voltage drop. Longer distances require larger wire sizes to maintain acceptable voltage levels. Our calculator accounts for the round-trip distance (positive and negative conductors) automatically.
Voltage drop is the reduction in voltage that occurs as current flows through wire resistance. The National Electrical Code (NEC) recommends limiting voltage drop to 3% for branch circuits and 5% for feeders. Lower voltage drops improve efficiency and equipment performance.
Copper wire has lower resistance than aluminum but costs more. Aluminum wire is lighter and less expensive but requires larger sizes for the same current capacity. Both materials are included in our calculations with appropriate resistance values.
Wire ampacity decreases at higher ambient temperatures. Our calculator applies temperature correction factors based on NEC standards:
While our calculator provides accurate wire sizing based on electrical principles, always consult local electrical codes and regulations. Additional factors may apply, including:
Use for sizing branch circuits, appliance connections, and service feeders in homes. Common applications include kitchen appliances, HVAC systems, electric vehicle charging, and workshop equipment.
Essential for motor feeders, lighting circuits, power distribution, and equipment connections in commercial and industrial facilities. Proper sizing ensures efficient operation and prevents costly downtime.
Critical for DC wiring in solar installations, battery connections, and inverter feeders. Proper wire sizing maximizes energy harvest and ensures system safety in renewable energy applications.
For complex installations, high-voltage applications, or when local codes have specific requirements, consult with a licensed electrician or electrical engineer. This calculator provides guidance but cannot replace professional expertise and code compliance verification.