StandardsMate™ calculators
Cable sizing, voltage drop, maximum demand, RCD trip tests, lighting layout and more. There are 12 calculators, from AS/NZS 3008 cable selection with the derating factors built in to AS/NZS 3500 drainage falls, each labelled with the standard or method it works from. No spreadsheets, and the assumptions behind each result are shown so you can check it against the job.
Try the calculators freeThe calculator suite
The calculations you reach for on a job, each labelled with the standard or method it works from. Pick one to open it. Every one of them is free with an account.
Compares cable sizes for your load, run length, installation method and derating, and shows the current capacity, voltage drop and earth size for you to check.
AS/NZS 3008.1.1OpenEstimates the voltage drop on a single or three-phase AC run from current, length and cable size, and flags when a larger size is needed.
AS/NZS 3008.1.1OpenAdds up connected loads with the Table C1 or C2 allowances for the supported installation types, with phase totals and a suggested main switch rating.
AS/NZS 3000 Appendix C (Tables C1, C2)OpenCompares a measured trip time with the reference limit for a general, non-delayed RCD. It does not certify an installation or decide what protection a circuit needs.
AS/NZS 61008.1 / 61009.1, tested per AS/NZS 3017OpenEstimates the total light output and an indicative LED wattage for a room from its type, dimensions, ceiling height and wall colour.
AS/NZS 1680OpenPlans a top-down downlight layout for rectangular or L-shaped rooms, with wall offsets and spacings in millimetres to mark out.
AS/NZS 1680OpenEstimates a downlight count and grid for a target lux level using the lumen method, with the utilisation and maintenance factors stated.
AS/NZS 1680OpenWorks the fall over a DN40 to DN150 drain run from a reference grade. Check the grade against the edition that applies to the job.
AS/NZS 3500.2OpenChecks hot water storage against the 60 °C Legionella minimum for the heater type, and names the kind of temperature control each outlet needs. It does not size or select a tempering valve.
AS/NZS 3500.4OpenIllustrates a simplified wind pressure for Regions A and B up to 10 m, from the wind region and terrain category. It is not a structural design and does not select members or fixings.
AS/NZS 1170.2OpenConverts airflow and room volume into air changes per hour, or airflow from a target you enter. It does not set a ventilation rate.
ArithmeticOpenEstimates boards, joints on joists, spares, joists and fixings for a rectangular deck, with a material take-off to print. No structural design.
Quantity estimateOpenGrounded in the standards
A calculator is only as good as the standard behind it. Each calculator here names the standard or method it works from and says what it does not cover, so you know what a number means before it goes on a compliance note.
Cable selection follows AS/NZS 3008.1.1. Current-carrying capacity is not a single tabulated figure: it is derated for the installation method, for grouping with other circuits, for ambient temperature, and for thermal insulation. Thermal insulation is the factor most often missed on site. A cable that carries a circuit comfortably in free air can fall short once it runs through a fully insulated ceiling.
Voltage drop is the second calculation, and AS/NZS 3000, the Wiring Rules, caps the total drop from the point of supply across the consumer mains, submains and final subcircuit combined. On a long run, voltage drop, not current capacity, decides the cable size. The cable you install has to satisfy both calculations: the larger answer wins.
For the full explanation of how the two calculations fit together, read the guide to cable sizing and voltage drop under AS/NZS 3008.
Why it matters
A calculation done at the quote is a calculation that saves a reorder, a callback and a hard conversation later.
Run the numbers at quoting, not after the reel is on the truck. A cable that falls short on a long run is a reorder and a return.
Each result names the standard or method it works from and lays out the inputs and assumptions behind it, so you can check it before it goes on a compliance note. The sign-off stays with you.
No formulas to keep current, no tabs that break when a tab is renamed. Open the calculator, enter the job, read the answer.
Every calculator is free with an account, from cable sizing to wind loading. Pro adds unlimited standards chat when you need it.
Get started free