DISCLAIMER

Disclaimer

Every number on this site is reference mathematics: the AWG formula, copper resistivity and published ampacity tables. It is not engineering advice and not a substitute for the electrical code in force where you live — plus the inspection and licensing rules that come with it.

• Mains-voltage work belongs to licensed electricians and permitted, inspected installations.
• Ampacity depends on insulation type, ambient temperature, raceway fill, continuous loading and local amendments; the tables here quote the NEC's baseline columns only.
• The calculator's voltage-drop model assumes simple linear runs and doesn't model harmonics, motor inrush, battery-cable transients or parallel conductor arrangements.
• Chassis/free-air ratings below 14 AWG are shop references, not code values, and are marked accordingly.

When the table and a licensed professional disagree, trust the professional — and when our table and the printed local code disagree, please tell us which edition you checked.

Last updated: October 2026.