Electrical Calculators
Quick reference calculators for voltage drop, cable sizing and maximum demand — built to show working, not just spit out a number.
Please note: General guidance only — verify against the current standard before relying on this result. Not a substitute for a licensed electrical design.
Voltage Drop Calculator
Enter current, cable length and size for an instant voltage drop result, working shown.
Open calculatorCable Size Calculator
Finds the smallest cable size that keeps voltage drop within your limit.
Open calculatorMaximum Demand Calculator
A simplified diversity estimate for planning switchboard and supply capacity.
Open calculatorRCD Trip-Time Reference Card
Maximum trip times and testing intervals under AS/NZS 3760, at a glance.
Open calculatorConduit Fill Calculator
Check what percentage of a conduit your cables fill against the common 40% guideline.
Open calculatorTransformer Sizing Calculator
Get the required kVA, nearest standard size, and full-load current for your load.
Open calculatorPower Factor Correction Calculator
Find the capacitor kVAR needed to correct your power factor to a target value.
Open calculatorShort-Circuit Current Calculator
Approximate three-phase fault current at a transformer's secondary terminals.
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