Estimate wire resistance from wire gauge, length, material, and temperature. This calculator also estimates voltage drop, voltage drop percentage, final voltage, power loss, ohms per 1,000 feet, and comparison scenarios.
Wire size:
The calculator uses the selected AWG or kcmil size to estimate circular mil area.
Material:
Copper and aluminum use different resistance constants.
Length:
The calculator adjusts conductor length based on whether you choose one-way, round-trip, or three-phase estimate.
A wire resistance calculator helps estimate how much resistance a wire run adds to a circuit.
It can help with voltage drop estimates, power loss estimates, wire sizing, low-voltage wiring, extension cords, DC circuits, solar wiring, feeders, electronics projects, and general electrical planning.
Your result shows estimated wire resistance, ohms per 1,000 feet, voltage drop, voltage drop percentage, final voltage, power loss, wire gauge, material, circular mils, conductor length, and comparison scenarios.
Wire resistance is the opposition to electrical current as it travels through a conductor. It is measured in ohms.
Yes. Longer wire has more resistance because current travels through more conductor length.
Yes. Larger wire has more conductor area and usually lower resistance. In AWG sizes, smaller gauge numbers mean larger wire.
Resistance causes voltage drop and power loss. In long runs or high-current circuits, too much resistance can reduce performance and create heat.