CableCalc beta

Enter your data – the calculator suggests the smallest copper cable size that keeps current within a basic ampacity and voltage drop limit.

AC / DC AC/DC is currently only shown for reference; calculation uses the same resistive model.

Voltage [V]

What is known?

Current (A) known Power (W) known

Current [A]

Cable length (one way)

Length unit Voltage drop is calculated over the round-trip (out & back).

Max voltage drop [%]

Preferred output

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Notes & limitations:

Assumes copper conductors, single circuit, free air / light installation.
Uses generic ampacity values (conservative but not a substitute for local electrical codes).
For mains or critical installations always have a qualified electrician verify the result.