Current Capacity · Voltage Drop · Derating
Select an appropriately sized cable based on design current, installation method, ambient temperature, grouping with other cables, and voltage drop. This calculator checks both current-carrying capacity and voltage drop, selecting whichever requires the larger conductor. Indicative current ratings are derived from published electrical engineering methodology — for final compliance sign-off, verify against the current edition of AS/NZS 3008.1.1.
Results for guidance only. Verify against current standards and manufacturer data.
Not a substitute for engineering judgement or a licensed professional.
Cable selection considers two independent checks: current-carrying capacity (thermal rating, derated for ambient temperature and grouping with other circuits) and voltage drop (if a cable length is provided). The cable is sized for whichever check governs — if voltage drop requires a larger conductor than the thermal rating alone, the larger size is selected and clearly flagged.