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Maximum Demand Calculator

Domestic & Commercial · Load Diversity

Calculate the maximum demand for an Australian domestic or small commercial installation by entering connected loads grouped by category. Diversity factors are applied per category — reflecting that not all connected loads operate simultaneously at full capacity — to estimate a realistic maximum demand figure for supply sizing. This calculator uses a lawful, general methodology rather than reproducing AS/NZS 3000 Table C1 verbatim; for formal compliance calculations, apply the actual published diversity factors from the current standard.

CALCULATOR

Maximum Demand

MAXIMUM DEMAND
10.6
kW
DEMAND CURRENT
46.1
Amps
Demand current assumes power factor = 1.0 (unity). For loads with a lower power factor, actual current will be higher than shown — use the Power/Current Converter with your load's actual power factor for a more accurate current figure.
TOTAL CONNECTED
10.6 kW
DIVERSITY FACTOR
1
BREAKDOWN BY CATEGORY
Lighting2000W → 2000W
General Power (GPO)3600W → 3600W
HVAC / Heating5000W → 5000W

Results for guidance only. Verify against current standards and manufacturer data.
Not a substitute for engineering judgement or a licensed professional.

Methodology

Loads are grouped by category. Within each category, the largest individual load is counted at 100%, and remaining loads in that category are counted at a diversity factor reflecting the likelihood they operate simultaneously at full capacity. This is a simplified general methodology and does not reproduce the specific diversity factors or worked calculation from AS/NZS 3000 Table C1, which is copyrighted Standards Australia material.

Data & Licensing Note

For formal compliance calculations submitted to a Distribution Network Service Provider (DNSP), you must apply the actual diversity factors and methodology published in the current edition of AS/NZS 3000. This calculator provides a useful estimate and understanding of the diversity concept but should not be used as the final compliance figure.

Assumptions & Limitations

  • Diversity factors used are simplified general approximations, not the specific AS/NZS 3000 Table C1 figures
  • Assumes balanced loading across phases for three-phase supplies
  • Does not account for demand response, solar export offset, or battery storage

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AusElectrical.tools
Built with reference to AS/NZS 3000, AS/NZS 3008, AS/NZS 1359
Results for guidance only — not a substitute for engineering judgement
Does not reproduce copyrighted Standards Australia material. Always consult current standards for compliance.