Introduction
Choosing between copper and aluminum wire is one of the most important decisions in electrical installations. Both materials have distinct advantages and disadvantages that make them suitable for different applications.
Copper Wire Advantages
Copper is the industry standard for most electrical applications:
- Higher Conductivity: Copper conducts electricity 64% better than aluminum
- Better Flexibility: More ductile and easier to bend, making installation simpler
- Superior Durability: Less prone to oxidation and corrosion
- Better Termination: Forms more reliable connections with standard devices
Aluminum Wire Advantages
Aluminum offers cost-effective alternatives for certain applications:
- Lower Cost: Can be 50-80% cheaper than equivalent copper wire
- Lighter Weight: Easier to handle and install, especially for large sizes
- Good for Large Conductors: Ideal for service entrance and feeder cables
Size Comparison
For the same current capacity, aluminum wire must be 2 AWG sizes larger than copper.
Size Comparison
Example: 10 AWG copper and 8 AWG aluminum both handle approximately 30A.
Best Applications for Each Material
Choose copper for:
- Residential branch circuits (lighting, outlets)
- Small to medium wire sizes (14-8 AWG)
- Locations requiring flexibility
- Applications where space is limited
Installation Considerations
Each material requires different installation techniques and considerations.
Important Safety Notes
Old aluminum wiring (pre-1972) in homes can be a fire hazard. Modern aluminum wire (post-1972) is safe when properly installed with CO/ALR rated devices.
Conclusion
Neither copper nor aluminum is universally better—each excels in different scenarios. Copper remains the standard for residential branch circuits due to its superior performance and ease of installation. Aluminum shines in large-conductor applications where cost savings justify the extra installation care required.
Use our Wire Gauge Calculator to calculate the right size for both copper and aluminum.