Free Electrical Tools & Calculators

Yes — every calculator on this page is completely free, with no sign-up and no ads. They're built by our Level 2 ASP team so you can plan a job or understand a defect notice before you call anyone.

Each tool applies the relevant Australian standard — AS/NZS 3000 for maximum demand, AS/NZS 3008 for cable sizing, or the SIRNSW tables for poles and struts — so results are a reliable starting point. They're estimates for planning purposes, not a certified design.

Yes. Every calculator here is an estimating and learning tool, not a replacement for a licensed assessment. Consumer mains, supply-side and metering work must be carried out by a Level 2 ASP electrician in NSW — send us your result and we'll confirm it on-site.

Start with the EV Charger Load Calculator to estimate charging time and load. If you want to see how it affects your whole property, run the Maximum Demand Calculator next — an EV charger over 10A is counted at 100% of its rating with no diversity.

It depends on what you want to keep running. Add up the running watts of your essential appliances, allow for the largest start-up surge, then add around 20% headroom. The Generator Load Calculator does this for you and suggests a Generac size — our team confirms it on-site.

Two checks decide it: the cable must carry your load current without overheating, and the voltage drop over the run must stay within limits. Whichever check demands the bigger cable wins — the Cable Size Calculator shows both side by side for every candidate size.

Maximum demand is the highest current your installation is expected to draw at any one time, after diversity is applied. It sets the size of your consumer mains, main switch and supply — the Maximum Demand Calculator works it out to AS/NZS 3000 Table C1 with the full working shown.