Calculator
Electrical Wire Size Calculator
What wire gauge do you need for your circuit?
Frequently Asked Questions
Why does distance matter for wire size?
Longer wire runs have more resistance, which causes voltage drop. If voltage drop exceeds 3%, appliances may not work properly and the wire generates excess heat. For long runs, you need to upsize the wire gauge to compensate. A wire that is safe at 25 feet may need to be one or two sizes larger at 100 feet.
About the Electrical Wire Size Calculator
Calculate the correct wire gauge for any electrical circuit based on amperage, distance, and voltage. Includes voltage drop calculation.