Electrical calculator
Wire Gauge Calculator
Estimate appropriate wire gauge based on amperage and length.
How the calculation works
Uses NEC guidelines: longer runs need larger wire to prevent voltage drop.
Example: 30A over 50 ft copper: use 10 AWG.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, medical circumstances, structural requirements, or other project-specific factors unless explicitly stated.
Frequently asked questions
How accurate is the wire gauge calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.