Electrical design

Wire size calculator

Use the target voltage drop to estimate a minimum conductor area for DC or AC circuits.

Worked example

A 12V circuit with 5A over 8 m one-way and 3 percent target drop

The minimum copper conductor size for that example is about 4.6 mm2, so the next standard size is typically selected.

Calculator

System voltage

Conductor material

Current (A)

One-way length (m)

Target drop (%)

Minimum wire size

0.0 mm2

Allowed drop

0.00 V

Loop length

0.0 m

Open the forward calculation page.

Read the guide for acceptable drop assumptions.

See a mains-specific target example.