Free wire size calculator for estimating copper conductor area from voltage, current, cable length, and permitted voltage drop.
Estimate minimum metric copper conductor area for a two-conductor DC or single-phase circuit. Enter voltage, current, one-way length, and maximum drop. The result rounds up to a common cross-section; check local codes before choosing cable.
Yes. The formula doubles it for outgoing and return conductors.
Copper at 20°C, using resistivity 0.0175 ohm·mm²/m. Conditions may require a larger conductor.
No. Also verify ampacity, protection, terminations, and local code with a qualified professional.