Cable Size Calculator
Recommends the smallest cable size that keeps voltage drop within your limit. Not an ampacity / current-carrying-capacity check — that's a separate confirmation.
Please note: General guidance only — verify against the current standard before relying on this result. Not a substitute for a licensed electrical design.
Cable size selector
Based on the AS/NZS 3008 mV/A/m voltage-drop method.
Recommended minimum size
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Final cable size must also satisfy current-carrying capacity (ampacity), installation method and thermal grouping — confirm against AS/NZS 3008 or with a licensed designer.
Export this result as a PDF
A clean, branded PDF of your inputs and result — handy for records or sending on.
Undersized cable is a common finding during aswitchboard upgradeinspection. Want to check the actual drop for a specific run instead of finding a minimum size? Use thevoltage drop calculator.
Need the real numbers signed off?
This tool is a starting point. Get a licensed design or on-site assessment for anything going to certification.
- Quote on the spot — a fixed price before work starts
- Booked in as soon as we can fit you in
- Certificate + asset register within 24h of completion
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