Concrete & Foundations
Concrete Footing Calculator
Estimates concrete for strip, spread, and trench footings
Updated May 13, 2026 · Live
What this tool does
Estimates concrete for strip, spread, and trench footings. IRC-compliant footing dimensions.
Calculates cubic yards of concrete required for a footing from its length, width, and depth.
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Formula Used
How the concrete footing calculator works
Estimates concrete for strip, spread, and trench footings. IRC-compliant footing dimensions. The calculator takes your dimensions and supplier rates, applies a standard US construction formula, and returns a quantity with an indicative cost. Every figure is an estimate — site conditions always move the final number.
Typical US concrete and foundations wastage
Ready-mix in cubic yards usually carries a 5–10% overage; bagged concrete (60 lb or 80 lb) typically needs around 10% extra for spills and short pours. The default reflects common US 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 building code compliance. Those remain the responsibility of a suitably qualified designer, engineer, or your local building official.
On-site considerations for concrete footing
Concrete placement is time-critical. Enough crew to place, consolidate and finish within the workability window matters, typically 60–90 minutes with Type I/II Portland cement.
Codes and compliance
Footings and structural slabs fall under the IRC (residential) or IBC (commercial), with reinforcing per ACI 318. Frost-line depths are set by your local jurisdiction, and a stamped plan covers any load-bearing pour. A pre-application question to the local building department gives early clarity, which is cheaper than a corrective inspection.
Before you order
Ready-mix is specified by strength (psi), slump, and aggregate size, with admixtures called out. For bagged work, a stock margin of around 10% over the calculated need covers part-bags, and bags keep best dry until placement. 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, labor-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 math.
Sources & methodology
This calculator estimates the volume of concrete needed for strip, spread, or trench footings using the formula V = L × W × D, where length and width are entered in feet and depth in inches. Mixed units are reconciled by dividing the product by 324 to return a result in cubic yards. A wastage fraction is added to the net volume to account for spillage and overpour during placement.
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 US 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 work that affects structure, building code compliance, gas, electrical, plumbing, or drainage to a public sewer, consult a licensed contractor or design 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.
Spotted something off?
Calculations or display — let us know.
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