/// Answer-first planning notes
How much concrete volume fits my entered footing geometry?
| Planning input | Calculation role | Field check |
|---|---|---|
| Footing quantity | Scales one footing volume | Count matching footing shapes only |
| Length, width, depth | Create net concrete volume | Use approved finished dimensions |
| Bag yield | Produces optional whole bags | Enter the selected product's stated yield |
Footing volume conversion uses the exact international foot while leaving structural design and product yield as explicit external inputs.
Evidence: National Institute of Standards and Technology/// Formula & field notes
How this concrete footing estimate works
FormulaNet volume = quantity × length × width × depth. Volume with waste = net volume × (1 + waste %). Bags = adjusted volume ÷ selected bag yield, rounded up.
Worked example
One 20 ft × 1.5 ft × 0.75 ft footing contains 22.5 ft³ (0.8333 yd³); with 10% waste and 0.60 ft³ per bag, order 42 bags.
Does one 20 ft × 1.5 ft × 0.75 ft footing produce 0.8333 yd³ net and 42 bags after 10% waste at 0.60 ft³ per bag?
Open exact inputs, intermediate values, rounding, and limitations
/// Source trail
Data & assumptions
Every source has a declared scope. A reference can support a conversion or product assumption without turning this estimate into a supplier quote.
Exact international-foot to meter conversion; U.S. survey-foot conversion is explicitly outside this claim.
Independent confirmation that one international foot equals exactly 0.3048 meters; U.S. survey-foot conversion remains distinct.
/// Common questions
Concrete Footing calculator FAQ
What should I verify before ordering footing concrete?
Confirm the approved finished footing dimensions, number of matching footings, selected concrete product, mixed yield, and supplier package size. ProjectQty keeps those inputs visible so the order can be checked before purchase.
How does waste affect the footing concrete estimate?
The entered allowance is applied to net footing volume before the result is divided by the selected bag yield and rounded up. Choose the allowance for the actual excavation, form, placement, and handling conditions; ProjectQty does not select it for you.
Is this footing concrete result a professional design?
No. It is a quantity-planning result. This tool cannot size a footing, determine soil bearing, select reinforcement, or establish structural or code compliance.