Table
Copper vs Aluminum Equivalent Resistance Sizes
Copper vs Aluminum Equivalent Resistance Sizes reference with assumptions and boundary notes.
Reference boundary
Resistance comparison only. This table does not provide ampacity equivalence, conductor substitution, terminal compatibility, or installation approval.
Reference table
Compare copper conductor areas with the minimum aluminum area needed for equal or lower resistance at 20 C.
| Copper size | Copper area (mm2) | Required aluminum area (mm2) | Minimum aluminum size | Aluminum area (mm2) | Boundary |
|---|---|---|---|---|---|
| 14 AWG | 2.08 | 3.41 | 10 AWG | 5.26 | Resistance-only comparison; not an ampacity or termination substitution |
| 12 AWG | 3.31 | 5.43 | 8 AWG | 8.37 | Resistance-only comparison; not an ampacity or termination substitution |
| 10 AWG | 5.26 | 8.62 | 6 AWG | 13.3 | Resistance-only comparison; not an ampacity or termination substitution |
| 8 AWG | 8.37 | 13.72 | 4 AWG | 21.2 | Resistance-only comparison; not an ampacity or termination substitution |
| 6 AWG | 13.3 | 21.8 | 3 AWG | 26.7 | Resistance-only comparison; not an ampacity or termination substitution |
| 4 AWG | 21.2 | 34.75 | 1 AWG | 42.4 | Resistance-only comparison; not an ampacity or termination substitution |
| 3 AWG | 26.7 | 43.77 | 1/0 AWG | 53.5 | Resistance-only comparison; not an ampacity or termination substitution |
| 2 AWG | 33.6 | 55.08 | 2/0 AWG | 67.4 | Resistance-only comparison; not an ampacity or termination substitution |
| 1 AWG | 42.4 | 69.51 | 3/0 AWG | 85 | Resistance-only comparison; not an ampacity or termination substitution |
| 1/0 AWG | 53.5 | 87.71 | 4/0 AWG | 107.2 | Resistance-only comparison; not an ampacity or termination substitution |
| 2/0 AWG | 67.4 | 110.49 | 250 kcmil | 126.7 | Resistance-only comparison; not an ampacity or termination substitution |
| 3/0 AWG | 85 | 139.34 | 300 kcmil | 152 | Resistance-only comparison; not an ampacity or termination substitution |
| 4/0 AWG | 107.2 | 175.74 | 350 kcmil | 177.3 | Resistance-only comparison; not an ampacity or termination substitution |
| 250 kcmil | 126.7 | 207.71 | 500 kcmil | 253.4 | Resistance-only comparison; not an ampacity or termination substitution |
| 350 kcmil | 177.3 | 290.66 | 600 kcmil | 304 | Resistance-only comparison; not an ampacity or termination substitution |
| 500 kcmil | 253.4 | 415.41 | 1000 kcmil | 506.7 | Resistance-only comparison; not an ampacity or termination substitution |
Use notes
- Use this table for preliminary reference and arithmetic checks only.
- Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.