Estimate the current an installation will actually draw by applying diversity to its connected loads — a working aid to the maximum demand assessment in AS/NZS 3000.
This is a simplified diversity estimate. A compliant maximum demand assessment must follow AS/NZS 3000 Appendix C (Tables C1/C2), which set specific rules and allowances per load group and installation type.
traqR keeps your electrical job details, quotes and certificates together — so the assessment behind a job is easy to find when you need it.
Start free trialGroup the installation’s loads — lighting, power outlets, cooking, water heating, air conditioning and other fixed loads — and enter the connected current of each.
Not everything runs at once, so each group gets a diversity allowance. Applying it to the connected load gives the demand that group actually contributes.
Summing the diversified loads gives the assessed maximum demand in amps, which sets the size of mains, switchgear and supply.
Maximum demand is the highest current an installation is expected to draw at any one time — always less than the total of every connected load, because not everything runs at once. It determines the size of the consumer mains, main switch, metering and supply, so getting it right avoids both undersized mains and paying for capacity you’ll never use.
Diversity recognises that loads don’t all operate simultaneously at full load. AS/NZS 3000 allows each group of loads to be assessed with an allowance — for example only counting a proportion of the power-outlet load — reflecting realistic usage. This tool lets you set a diversity percentage per group.
AS/NZS 3000 Appendix C sets out the method in Tables C1 (single-domestic) and C2 (other installations), with specific rules and allowances for each load group and installation type. It’s more detailed than a single diversity percentage — this tool is an aid to understanding and estimating, not a replacement for that calculation.
Not on its own. Use it to get a feel for the demand, then carry out the formal Appendix C assessment and have a licensed electrician design and verify the installation. Mains and switchgear sizing must comply with AS/NZS 3000.
This calculator is a simplified estimate using a single diversity factor per load group. It is not a substitute for the maximum demand assessment in AS/NZS 3000 Appendix C. All electrical design must be carried out and verified by a licensed electrician.
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