The Copper vs Aluminum Wire Size Converter takes a wire of one metal and returns the equivalent size in the other metal, both for equal current capacity and for equal voltage drop (resistance).
Copper vs Aluminum Wire Size Converter
Convert a copper wire size to the aluminum size with equal capacity, and vice versa. Compare cross-section, resistance and ampacity between copper and aluminum conductors.
Inputs
Result
--
equal ampacity
--
equal resistance
About Copper vs Aluminum Wire Size Converter
Features
- Copper to aluminum and back
- Equal-ampacity equivalent
- Equal-resistance equivalent
- Shows area and ampacity of each
How to Use
- Pick the source metal and wire size.
- Read the aluminum/copper equivalents.
- Compare area and ampacity.
Examples
Example: 12 AWG copper (25 A) -> 10 AWG aluminum for equal ampacity.
Benefits
- Quick Cu/Al substitution
- Avoid undersizing when substituting metals
Frequently Asked Questions
Why is aluminum a different size?
Aluminum has about 61% of copper conductivity, so it needs roughly 1.6 times the cross-section for the same resistance.
What is the equivalent size?
This tool gives two equivalents: one for equal ampacity (current carrying) and one for equal resistance (same voltage drop).
Is aluminum safe?
Yes when sized and terminated correctly with antioxidant paste and listed connectors. Always follow code.
Is my data saved?
No. All math runs in your browser.