Electrical Calculators Australia
Free electrical calculators built for Australian conditions and standards. Check cable voltage drop against AS/NZS 3000 Wiring Rules, or size a solar panel system for any Australian state or territory. All calculators are metric and reference current Australian standards.
Electrical calculators
Voltage Drop Calculator
Single-phase and three-phase voltage drop check against AS/NZS 3000 Clause 3.6.2. Finds minimum compliant cable size.
Open calculator →Solar Panel Calculator
Recommended system size in kW, panel count, annual output, and estimated net cost after STC rebate — by state.
Open calculator →Australian electrical standards reference
- AS/NZS 3000:2018 (Wiring Rules) — The primary Australian/New Zealand standard for electrical installations. Clause 3.6.2 sets the 5% maximum voltage drop limit. All licensed electrical work must comply.
- AS/NZS 3008.1.1 — Selection of cables for alternating voltages up to and including 0.6/1 kV. Contains current-carrying capacity and voltage drop tables used for cable selection.
- AS/NZS 5033 — Installation and Safety Requirements for Photovoltaic (PV) Arrays. The governing standard for solar panel wiring, earthing and isolation in Australia.
- AS/NZS 4777 — Grid Connection of Energy Systems via Inverters. Covers requirements for grid-connected solar inverters and battery storage systems, including anti-islanding protection.
- NCC (National Construction Code) — References AS/NZS 3000 for electrical work in new buildings and sets minimum requirements for electrical services in residential and commercial construction.
Common Electrical Questions
Do I need a licensed electrician for all electrical work in Australia?
Yes. In all Australian states and territories, any electrical wiring or connection work must be carried out by a licensed electrician. Homeowners can replace light globes, batteries, and plug-in appliances, but any work involving fixed wiring — including new circuits, outlets, switchboards, and solar connections — requires a licensed electrical contractor. Performing unlicensed electrical work is illegal and void for insurance purposes. Check licensing requirements with your state's electrical safety authority (e.g. Energy Safe Victoria, NSW Fair Trading, QBCC).
What is the maximum voltage drop allowed in Australia?
AS/NZS 3000:2018 Clause 3.6.2 sets the maximum allowable voltage drop at 5% of the nominal supply voltage from the point of supply to any point of utilisation. For 230 V single-phase, this is 11.5 V. Many designers use 2.5% for sub-mains and 2.5% for final circuits to stay within the 5% total. Use the Voltage Drop Calculator above to check compliance for your cable run.
How many solar panels can I fit on an average Australian roof?
A typical 200 m² Australian home can fit 20–30 panels on usable north-facing roof area, depending on pitch, shading, and setback requirements (AS/NZS 5033 requires a minimum 300 mm clearance from roof edges). At 400 W per panel, that gives 8–12 kW of capacity. Roof area is more often the limiting factor than electricity consumption for larger households. The Solar Panel Calculator above estimates panel count based on your daily usage and state.