Voltage Drop Calculator
Check voltage drop percentage for cable runs against AS/NZS 3000 limits — 3% for sub-mains, 5% for final sub-circuits.
For reference only — always verify with the current published standard and consult a licensed electrical engineer for critical installations.
Voltage Drop Inputs
About This Voltage Drop Calculator
This calculator checks whether your cable run stays within the allowable voltage drop limits. Designed for Australian sparkies sizing sub-mains and final sub-circuits on residential and commercial jobs.
Use it when you know the cable size and need to confirm the voltage drop percentage before pulling cable. Handy for long runs, shed supplies, and any circuit where drop is borderline.
Voltage drop values are based on mV/A/m tables from AS/NZS 3008.1.1 and checked against the 5% total limit in AS/NZS 3000. This is a reference tool. Verify results against the current edition of the standard.
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