ruchira
// ENGINEERING TOOL

Cable voltage drop calculator

Calculate voltage drop for copper and aluminium cables in DC, single-phase and three-phase circuits, in mm² or AWG, and find the smallest cable that passes.

  • Free
  • No sign-up
  • Private: runs in your browser
// HOW IT WORKS

4 steps, no sign-up.

Built and maintained by Ruchira Sachinthana. Spotted a bug or want a feature? Tell me.

  1. 01Pick DC, single-phase or three-phase, and the supply voltage.
  2. 02Enter the load current, the one-way cable length and the conductor.
  3. 03Choose the cable size in mm² or AWG.
  4. 04Compare the drop against your limit and use the suggested size if it fails.
// FAQ

Voltage drop calculator: questions, answered.

Something else? Ask on WhatsApp.

Many wiring rules allow about 3% for lighting and 5% for other circuits from the origin of the installation. Check the code that applies where you work.

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// CUSTOM TOOLS

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