Select a cable size that satisfies both current capacity and voltage drop.
Cable selection must satisfy two independent criteria, and the larger requirement wins. Short heavy-current runs are governed by ampacity; long runs are almost always governed by voltage drop. Knowing which criterion governs tells you what to change: a shorter route helps a voltage-drop limited circuit, while better ventilation helps an ampacity-limited one.
Cable Size
Area is the larger of that needed for ampacity and that needed to hold voltage drop within limits
Area is the larger of that needed for ampacity and that needed to hold voltage drop within limits Cable selection must satisfy two independent criteria, and the larger requirement wins. Short heavy-current runs are governed by ampacity; long runs are almost always governed by voltage drop.
Knowing which criterion governs tells you what to change: a shorter route helps a voltage-drop limited circuit, while better ventilation helps an ampacity-limited one.
This calculator takes 5 inputs: Design current, Route length, Nominal voltage, Permitted voltage drop, Phases. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.