Voltage Drop Calculator

Voltage Drop Calculator is a browser-based tool for electricians, engineers and students. Enter the load in amps, watts or horsepower, the voltage from 12V DC to 480V three-phase, copper or aluminum, conduit type and one-way run length. It returns the voltage drop, end voltage and a suggested wire size checked against the 3% and 5% reference limits. Results are estimates and do not replace a code review.