Commercial copper PVC, XLPE and 110°C EPR sub-mains and final sub-circuits. 7 install methods, ambient + grouping derate, parallel cables, harmonic neutral, voltage drop and earth conductor. Aligned to AS/NZS 3008.1.1 and AS/NZS 3000:2018 + Amd 2:2021.
Calculator updates live as you edit. Click the install method label to pick from diagrams.
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Base rating per AS/NZS 3008.1.1 for the selected cable construction, insulation and install method. Derated for ambient temperature, grouping, parallel cables and harmonic loading.
mV per ampere per metre from AS/NZS 3008.1.1, multiplied by design current, length and power factor (divided by 1000). Checked against the AS/NZS 3000 Cl 3.6.2 5% combined limit.
Minimum copper earthing conductor from AS/NZS 3000 Table 5.1 Method 1 based on the selected active cross-section. Earth fault loop impedance check is NOT performed.
CCC Engineering delivers commercial electrical design from concept to CC submission — cable schedules, switchboard schedules, single-line diagrams, lighting design, essential services and full IFC documentation.
This cable sizing calculator helps electrical engineers, electrical contractors and licensed electricians size cables for commercial and industrial sub-mains and final sub-circuits in Australia and New Zealand. Enter the design current (or kW/kVA with power factor), pick the cable construction, insulation type and install method that matches your installation, set the ambient temperature and grouping, and the tool will pick the smallest copper cable that satisfies AS/NZS 3008.1.1 current-carrying capacity and the AS/NZS 3000 voltage drop limit.
The current-carrying capacity is the table base rating multiplied by the ambient temperature factor, grouping factor for the selected install method, parallel cable count and harmonic loading derate. Voltage drop uses the tabulated mV per ampere per metre value for the selected cable, multiplied by design current, route length and power factor, divided by 1000, then expressed as a percentage of the nominal line-to-line voltage. The earth conductor is sized using AS/NZS 3000 Table 5.1 Method 1.
This tool is suitable for preliminary design, fee proposal sizing and verification of existing cable schedules. It does NOT perform earth fault loop impedance disconnection-time analysis, RCD selection, discrimination, AS/NZS 3013 fire-rated cabling, motor starting current sizing, or short-circuit fault rating. For binding CC-submission design, the result must be checked by a qualified electrical engineer or licensed electrical contractor. If you'd like CCC Engineering to take on the design, the enquiry form above is the quickest way to get in touch.