Free Electrical Calculators
Built for Australian Electricians
Cable sizing, voltage drop, maximum demand and more — 100% free, mobile-friendly, and always up-to-date with Australian Standards.
Calculators
Cable Sizing Calculator
AS/NZS 3008.1.1:2025
Auto-size cables for current rating, voltage drop, and earth fault loop impedance.
Voltage Drop Calculator
AS/NZS 3008.1.1:2025
Check voltage drop compliance for any cable size, length, and load.
Maximum Demand Calculator
AS/NZS 3000:2018
Calculate maximum demand using Tables C1 and C2 for residential and commercial.
NewConduit Fill Calculator
AS 2053 + AS/NZS 3000
Check cable fill percentage and find minimum conduit size for your cable run.
Earth Conductor Sizing
AS/NZS 3000:2018
Size earth conductors using Table 5.1 or the adiabatic equation.
SolarVoltage Rise Calculator
AS/NZS 4777.1:2024
Solar PV voltage rise and export limit calculation for grid-connected inverters.
First in AUEV Charger Cable Sizing
AS/NZS 3000:2018 + 3001.1
Cable and breaker sizing for EV charger installations. First AU/NZ dedicated tool.
Circuit Breaker Sizing
AS/NZS 3000:2018
Select the correct breaker rating and curve for any circuit.
Power Factor Correction
AS/NZS 61000.3.100
Calculate capacitor bank size to correct power factor and reduce energy costs.
Transformer Sizing
AS 2374 / AS 60076
Size transformers for any load with demand factors, growth planning, and protection.
Motor Calculator
AS/NZS 3000:2018 + 1359
Full load current, cable sizing, breaker selection, and starter sizing for motors.
Lighting Load Calculator
AS/NZS 3000:2018 + AS 1680
Calculate lighting circuit loads, number of circuits, and W/m² compliance.
Battery/UPS Sizing
AS 62040 + AS/NZS 3000
Size UPS and battery banks for backup power with derating and runtime calculations.
SafetyEmergency Lighting
AS/NZS 2293.1
Calculate emergency luminaire count, exit signs, spacing, and battery sizing.
PopularSolar PV Sizing
AS/NZS 4777.2 + 5033
Full solar system sizing — panels, inverter, yield, payback, and export limits.
AU + NZRCD Selection Guide
AS/NZS 3000:2018
Select the right RCD type and sensitivity for any circuit. Includes NZ Type A mandate.
Earthing System Design
AS/NZS 3000:2018 S5
Design earth electrodes — rod, strip, plate, ring — with touch/step voltage checks.
IDMT Protection Relay
IEC 60255 / AS 60255
Calculate operating time for all 5 IEC inverse curves — SI, VI, EI, LTI, DT.
Three-Phase Power
Utility Calculator
Convert between voltage, current, and power for three-phase star and delta systems.
Full Load Current
AS/NZS 3000 + 3008
Calculate FLC for motors, transformers, heaters, and lighting with breaker recommendations.
Motor Speed Calculator
IEC 60034
Synchronous and actual speed for any pole count, frequency, and motor type.
Motor Torque Calculator
AS/NZS 1359 + IEC 60034
Full load, starting, breakdown, and pull-up torque for all motor and starter types.
Transformer Fault Current
IEC 60909
Three-phase and single-phase fault current, peak current, and fault MVA at secondary.
Generator Sizing
AS/NZS 3010:2014
Size generators for motor starting, altitude/temperature derating, and fuel consumption.
PremiumArc Flash Calculator
IEEE 1584:2018
Incident energy, arc flash boundary, and PPE category per IEEE 1584:2018.
Why ElecCalc beats the alternatives
| Feature | jCalc | ElecAS | ElecCalc ✦ |
|---|---|---|---|
| Price | A$265/year | Free | 100% Free |
| AS/NZS 3008:2025 | ❌ 2017 only | ❓ Unclear | ✅ Day one |
| Works on mobile | ❌ Desktop only | ⚠️ Partial | ✅ Mobile-first |
| Works offline | ❌ | ❌ | ✅ PWA |
| PDF export | 💰 Paid only | ❌ | ✅ Free |
| No login needed | ✅ | ✅ | ✅ |
| AI guidance | ❌ | ❌ | ✅ Pro |