Free Australian electrical calculators
25 tools for cable sizing, voltage drop, arc flash, earthing, and more. Built for AS/NZS 3008.1.1:2025. No login. No paywall.
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Voltage drop, single phase 230 V
Voltage drop
5.10%
11.81 V drop
OVER 5%AS/NZS 3000 limit
Gordon McCartin
Electrical tutor and trainer
Need a hand with the theory
One-on-one electrical tutoring
Expert one-on-one electrical tutoring sessions tailored to your exact learning needs, from basic circuits to advanced industrial systems. Perfect for apprentices, students, and professionals.
- Years teaching
- 40+Years teaching
- Students helped
- 180+Students helped
- States licensed
- 3States licensed
- Per hour, from
- $80Per hour, from
Licensed electrical contractor, Cert IV in Training and Assessment, and Working with Children verified. Apprenticeship support, capstone projects and AS/NZS 3000 refreshers.
25 tools, every one of them free
Cable sizing through arc flash analysis. All built for Australian and New Zealand standards.
Core Calculations
Essential tools for every jobCable Sizing
AS/NZS 3008.1.1:2025
Auto-size cables for current rating, voltage drop, and earth fault loop impedance.
Open calculatorVoltage Drop
AS/NZS 3008.1.1:2025
Check voltage drop compliance for any cable size, length, and load.
Open calculatorMaximum Demand
AS/NZS 3000:2018
Calculate maximum demand using Tables C1 and C2 for residential and commercial.
Open calculatorConduit Fill
AS 2053 + AS/NZS 3000
Check cable fill percentage and find the minimum conduit size.
Open calculatorEarth Conductor
AS/NZS 3000:2018
Size earth conductors using Table 5.1 or the adiabatic equation.
Open calculatorCircuit Breaker
AS/NZS 3000:2018
Select the correct breaker rating and curve for any circuit.
Open calculatorProtection & Safety
Safety-critical calculationsArc Flash
IEEE 1584:2018
Incident energy, arc flash boundary, and PPE category.
Open calculatorHigh DemandEarthing System
AS/NZS 3000 S5
Design earth electrodes with touch and step voltage checks.
Open calculatorAU + NZRCD Selection
AS/NZS 3000:2018
Select the right RCD type and sensitivity. Includes NZ Type A mandate.
Open calculatorIDMT Relay
IEC 60255
Operating time for all 5 IEC inverse curves.
Open calculatorEmergency Lighting
AS/NZS 2293.1
Luminaire count, exit signs, spacing, and battery sizing.
Open calculatorSolar & EV
Renewables and electric vehiclesSolar PV Sizing
AS/NZS 4777.2 + 5033
Full solar system sizing covering panels, inverter, yield, payback, and export limits.
Open calculatorVoltage Rise
AS/NZS 4777.1:2024
Solar PV voltage rise and export limit calculation for grid-connected inverters.
Open calculatorFirst in AUEV Charger Sizing
AS/NZS 3000 + 3001.1
Cable and breaker sizing for EV charger installations.
Open calculatorMotors & Power
Industrial and commercialMotor Calculator
AS/NZS 3000 + 1359
Full load current, cable sizing, breaker selection, and starter sizing.
Open calculatorThree-Phase Power
Utility
Convert between voltage, current, and power for star and delta systems.
Open calculatorFull Load Current
AS/NZS 3000 + 3008
Calculate FLC for motors, transformers, heaters, and lighting.
Open calculatorMotor Speed
IEC 60034
Synchronous and actual speed for any pole count and frequency.
Open calculatorMotor Torque
AS/NZS 1359 + IEC 60034
Full load, starting, breakdown, and pull-up torque calculations.
Open calculatorPower Factor
AS/NZS 61000.3.100
Calculate capacitor bank size to correct power factor.
Open calculatorTransformers & Generators
Sizing and fault analysisTransformer Sizing
AS 2374 / AS 60076
Size transformers with demand factors, growth planning, and protection.
Open calculatorTransformer Fault
IEC 60909
Three-phase and single-phase fault current at transformer secondary.
Open calculatorGenerator Sizing
AS/NZS 3010:2014
Size generators for motor starting, derating, and fuel consumption.
Open calculatorWhy sparkies choose ElecCalc
$0
No paywall, no subscription
jCalc charges A$265/year. ElecCalc is free forever.
2025
AS/NZS 3008.1.1 day-one
Most competitors still reference the 2017 edition.
25
Calculators and growing
More than any free Australian competitor.
PWA
Works offline on your phone
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