Concrete / Footing quantity
Concrete Footing Calculator
Calculate concrete volume for continuous strip footings, rectangular pads, or circular pier footings. Add a product yield for whole bags or your own rate for a material-cost estimate.
Estimate footing concrete
Choose a footing shape and enter dimensions from your drawings or project requirements.
Footing dimensions
Use 1 when the entered length is the total continuous run.
Blank means 0%. Choose an allowance for the job; no percentage is prescribed.
Concrete quantities
- Total footing base area
- 5 m²
- Volume per footing
- 1.25 m³
- Net concrete volume
- 1.25 m³
- Net concrete in yards
- 1.634938274 yd³
- Allowance volume
- 0 m³
- Estimated ordering volume
- 1.25 m³
- Estimated order in yards
- 1.634938274 yd³
Bags and material cost — optional
Use the cured-volume yield printed on the exact product label. Bag mass alone does not establish yield.
Enter a ready-mix rate or a price per bag. Leave blank for quantities only.
Currency labels do not convert exchange rates or supply local prices.
Bag estimate
- Whole bags required
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- Volume supplied by bags
- —
- Volume above estimated order
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Concrete material cost
- Estimated material cost
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View copyable summary
ConstructGauge — Concrete Footing Calculator Footing shape: continuous / strip Length: 10 m Width: 0.5 m Depth: 0.25 m Identical footings: 1 Net concrete: 1.25 m³ / 1.634938274 yd³ Allowance (0%): 0 m³ Estimated order: 1.25 m³ / 1.634938274 yd³ Quantity estimate only. Dimensions must come from project requirements. Does not determine footing size, depth, reinforcement, bearing capacity, structural adequacy or code compliance.
Method
How footing concrete is calculated
Start with footing dimensions already established by your drawings or project requirements. Select the matching shape, enter the depth and count, and keep all measurements in their stated units.
- Strip or pad base area = length × width
- Circular base area = π × (diameter ÷ 2)²
- Volume per footing = base area × depth
- Net concrete volume = volume per footing × identical footing count
- Estimated ordering volume = net volume × (1 + allowance percentage ÷ 100)
The engine converts dimensions to metres before calculating and keeps full precision until display. One cubic yard is 0.764554857984 cubic metres.
Worked example
A 10 m continuous footing
A footing 10 m long, 0.5 m wide and 0.25 m deep has a base area of 5 m². Its net volume is 1.25 m³. A user-selected 8% allowance adds 0.1 m³, producing an estimated ordering volume of 1.35 m³.
At an illustrative concrete-only rate of 150 per m³, the material cost is 202.50 in the selected currency. Neither the rate nor the allowance is a recommendation.
Circular pier-footing example in Imperial units
Four circular footings, each 24 in in diameter and 36 in deep, contain 12π ft³ of concrete in total. That equals approximately 37.6991 ft³ or 1.3963 yd³ before an allowance.
Using bag yield correctly
Premixed concrete bags with different products or bag masses can provide different cured volumes. Enter the yield printed by the manufacturer for the exact product. The calculator divides the estimated ordering volume by that yield and rounds upward to a whole bag.
For example, 1.25 m³ divided by a stated yield of 25 L per bag is exactly 50 bags. An estimated order of 1.26 m³ requires 51 bags, which provide 1.275 m³ at that stated yield. Bag calculations do not estimate added water or change the manufacturer’s mixing instructions.
Net quantity, ordering allowance and material cost
Use net volume as the geometric concrete quantity for an initial quantity schedule. Keep any ordering allowance visible as a separate procurement choice. Over-excavation, uneven ground and supplier order increments can affect what is actually ordered, but this calculator does not prescribe an allowance.
The optional cost is concrete material only. It excludes excavation, reinforcement, formwork, labor, delivery, short-load charges, pumping, finishing, taxes and other project-specific costs. Currency selection labels your rate; it does not retrieve regional prices or exchange rates.
Measuring continuous footing runs
Use the scheduled footing dimensions from the project documents for the net BOQ quantity. When a constant-width footing turns through corners, measure its run along the centreline. Adding outside-face lengths counts extra material at the corners, while inside-face lengths omit material.
If widths or depths change, divide the footing into non-overlapping sections and calculate each section separately. Compare the excavated trench with the specified geometry when choosing an allowance. If you enter measured excavation dimensions instead, do not add the same over-excavation again through the allowance field.
Concrete footing calculator FAQ
Does this calculator choose the correct footing size?
No. Enter dimensions from project drawings or requirements. The calculator only converts those dimensions into concrete quantities.
Can it calculate strip, pad and pier footings?
Yes. Continuous or strip and rectangular pad footings use length × width × depth. Circular pier footings use π × radius² × depth.
Should I enter the total strip-footing length?
Yes. If you already added all continuous runs, enter that total and use a count of one. Use the count for repeated identical runs or elements.
How many bags of concrete do I need?
Enter the estimated ordering volume and the cured-volume yield shown on the selected product. The calculator rounds the result upward to a whole bag.
Does a bag’s weight determine its concrete yield?
No. Products of similar mass may state different yields. Use the manufacturer’s published yield for the exact bag rather than deriving it from weight alone.
Does the estimate include rebar or excavation?
No. Reinforcement, excavation, formwork and other work require separate project information and are outside this concrete-material estimate.
Can I combine footing and slab concrete?
Calculate the footing and slab as separate non-overlapping volumes, then add the net quantities if they belong in the same total. Thickened edges and monolithic details must be divided carefully so the shared concrete is not counted twice.
Calculation basis and limits
The volume formulas use elementary rectangular and circular geometry. They do not establish load capacity, soil bearing conditions, frost depth, reinforcement, strength or structural suitability. Confirm those requirements before using the quantity for procurement.
Unit conversions use international feet, inches and yards. See NIST’s SI conversion-factor reference for the conversion basis; it does not certify this calculator or its construction assumptions.