Concrete Footing Calculator
Estimate concrete volume for continuous or repeated rectangular footings with waste allowance and bag estimates
Concrete required
How we calculated it
About the Concrete Footing Calculator
Concrete footing estimates focus on the volume of concrete below a wall, column or structural support. Footing length, width and thickness determine the basic pour volume, and multiple isolated footings can be added together.
The calculator is for material quantity, not structural sizing. Footing dimensions, reinforcement, frost depth and soil bearing requirements should come from the project design or applicable code.
How to Use the Concrete Footing Calculator
- Enter footing length, width and thickness.
- Enter the number of identical footings when applicable.
- Add a realistic concrete waste allowance for over-excavation, form variation and spillage.
- Calculate cubic yards, cubic metres or bag equivalents and round according to supplier delivery rules.
How the Calculation Works
For a rectangular footing, volume = length × width × thickness. Multiple identical footings multiply that volume by quantity.
After units are normalized, the calculator converts cubic feet to cubic yards by dividing by 27 or converts metric volume as required. Waste is applied after net geometric volume is found.
Worked example
Concrete Footing Calculator Worked Example
40 ft footing, 2 ft wide and 10 in thick
10 inches = 0.8333 ft. Volume ≈ 40×2×0.8333 = 66.67 ft³. In cubic yards, 66.67÷27 ≈ 2.47 yd³ before waste.
Result guide
Understanding Your Concrete Footing Calculator Result
The result is concrete volume only. Excavation, gravel base, reinforcing steel and formwork are separate quantities even though they are part of the same footing project.
Before you rely on the answer
Assumptions and Limitations
- Entered dimensions come from an approved or suitable design.
- Footing geometry is adequately represented by the selected shape.
- Waste allowance is separate from structural dimensions.
Practical tip
Using This Result in Practice
Measure thickness in the same unit system before multiplying. Inches accidentally treated as feet can multiply the concrete order dramatically. For ready-mix, also check minimum-load and short-load policies.
Related calculations
Useful Calculations to Continue With
If reinforcing steel quantity must also be estimated, use the Rebar Calculator separately.
If you need the soil-removal volume for the footing excavation, use the Excavation Calculator.
Common questions
Concrete Footing Calculator FAQ
How do I calculate concrete for a strip footing?
Multiply footing length, width and thickness, then convert the cubic volume to the desired unit.
Should I add waste to footing concrete?
Usually a modest allowance is practical because excavation and placement are not perfectly exact.
Can this calculator size the footing structurally?
No. Structural dimensions depend on loads, soil bearing, reinforcement and code requirements.