Voltage Drop Calculator

Free voltage drop calculator for AC and DC circuits. Enter amps, voltage, run length and wire size to get the drop, end voltage and a suggested conductor size. VoltageDropCalculator.net is a free, browser-based voltage drop calculator for electricians, engineers and students. Enter load (amps, watts or HP), voltage (12V DC to 480V 3-phase), copper or aluminum, conduit type and one-way length to see the voltage drop, end voltage and a wire size checked against 3%/5% limits.