Concrete & Foundations
Concrete Footing Calculator
Estimates concrete for strip, pad, and trench footings
Updated 26 June 2026 · Live
What this tool does
Estimates concrete for strip, pad, and trench footings.
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How the concrete footing calculator works
Estimates concrete for strip, pad, and trench footings. The calculator takes your dimensions and supplier rates, applies a standard Australian trade formula, and returns a quantity with an indicative cost. Every figure is an estimate — site conditions always move the final number.
Typical Australian concrete and foundations wastage
Wastage on concrete typically runs 5–10% on volumes poured from ready-mix, rising toward 15% in short discontinuous pours where part-loads are unavoidable. The default reflects common Australian trade practice and can be edited up for non-standard geometry or down where experience supports a lower figure.
What this tool does not do
It does not replace a professional quote, factor regional pricing, assess structural adequacy, or confirm National Construction Code (NCC) compliance. Those remain the responsibility of a suitably qualified designer, surveyor, or your building surveyor.
On-site considerations for concrete footing
Concrete placement is time-critical. Enough labour to place, consolidate and finish within the workability window matters, which is typically 60–90 minutes with standard OPC.
the National Construction Code (NCC) and compliance
Structural elements (foundations, retaining walls, structural slabs) fall under the National Construction Code. Calculations from a chartered structural engineer are typically required before breaking ground on anything load-bearing. A pre-application enquiry to the local council can give early clarity, which tends to be less costly than retrospective correction.
Before you order
Ready-mix is ordered by volume (m³) with a clear specification: C-grade, slump, aggregate size, and admixtures. For bagged concrete, a stock margin of around 10% over the calculated need covers part-bags. Cross-checking the calculator’s output against a supplier quote helps catch differences in pricing assumptions — a quote listing exact product specifications (grade, finish, batch number) with confirmed delivery timescales is easier to reconcile against a programme.
Adjusting the defaults
Every input in this calculator is editable. Enter your own dimensions, supplier prices, and wastage allowance — the output recalculates instantly. If the defaults feel off for your region or project type, your own numbers always override them.
Using this concrete footing calculator alongside other BuildMetricLab tools
This calculator works best as part of a planning workflow. Pair the quantity with our project contingency, labour-hours, and material-cost calculators to build a complete estimate before you pick up the phone to a supplier. All BuildMetricLab tools run entirely in your browser — no sign-up, no data sent anywhere, and every formula is shown on-page so you can audit the maths.
Sources & methodology
Estimates concrete for strip, pad, and trench footings. Every result is calculated from the values you enter, and all inputs are editable.
Frequently asked questions
Are concrete footing calculator results accurate enough to order materials?
Use them as a starting estimate only. Verifying the final quantity with your supplier or contractor before ordering is good practice — site conditions, wastage and cut-offs all affect the true figure.
What wastage percentage should I use?
The calculator defaults to the typical Australian trade allowance for concrete & foundations. A higher allowance suits complex cuts, awkward shapes, or first-time DIY. The default wastage allowance reflects common trade practice; values lower than the default may underestimate offcuts.
Does this replace professional advice?
No. This tool is a planning estimator. For works that affect structure, the National Construction Code (NCC), boundary or dividing-fence, gas, electrics, drainage to a sewer, or similar, consult a suitably qualified professional.
Can I change the unit prices?
Yes — every price field is editable. Entering your supplier's quote gives a total that matches your project.
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