Voltage Drop Calculator
Calculate voltage drop in cables for DC and single-phase AC circuits.
This is a resistive estimate at about 20°C (copper 1.68e-8 and aluminium 2.82e-8 Ω·m) and ignores cable reactance, temperature and power factor. Divide the drop by your supply voltage to get a percentage, and compare it with the limit in your wiring code or your electrician's design.
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