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Footing Concrete Calculator

Calculate footing concrete volume, bags and weight — cubic yards/feet, 40/60/80-lb bags vs ready-mix, weight and cost with density and waste. Enter dimensions, select units and add waste to get instant, supplier-ready numbers.

1. Measurements & Dimensions

2. Material Properties & Waste Allowance

3. Optional Material Cost

FOOTING CONCRETE CALCULATOR ESTIMATE
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Enter dimensions above to calculate

Calculation Breakdown & StepsFormula: V = length × width × thickness × identical sections
  1. Enter values to see step-by-step substitution.

    Engineering Assumptions:

    • Rectangular sections of uniform thickness. Split irregular shapes into non-overlapping rectangles.
    • Thickness and reinforcement must come from project plans; volume alone does not establish load capacity.
    VISUAL GUIDE — FOOTING CONCRETE CALCULATORfoundation · footing-concrete-calculator

    TOP VIEW — Length × Width

    Footing Concrete Calculator topLength 17ftWidthFooting Concrete17×9 = 153 ft²

    SECTION — Placed thickness 3in

    Footing Concrete Calculator sectionFooting Concrete 3in3"V = length × width × thickness × identical sections · +7% → 1.52 yd³
    Footing Concrete Calculator — V = length × width × thickness × identical sections · example 17×9 @3in = 38.3 ft³ (1.42 yd³) → 1.52 yd³ with 7% waste · footing-concrete-calculator

    What Is This Calculator?

    The Footing Concrete Calculator — Estimates foundation excavation, footings and walls for US homes — volume, concrete and cost.

    What Does It Calculate?

    • Footing volume in cubic yards
    • Foundation wall area and concrete
    • Excavation volume with waste

    How to Use the Calculator

    1. Measure Footing Concrete 20 ft x 10 ft x 4 in — use feet for length/width and inches for thickness where typical.
    2. Enter values and select units. The calculator converts to feet before calculating (inches /12, yards x3).
    3. Adjust waste % and optional price, then click Calculate. Results show with waste included.
    4. Use Reset to clear and try another size.

    Formula & Engineering Methodology

    V = length × width × thickness × identical sections

    • L — Length for Footing Concrete in feet
    • W — Width for Footing Concrete in feet
    • D — Depth for Footing Concrete in feet

    All units convert to exact standard engineering dimensions (NIST SP 811) before calculation to ensure consistency between US Customary and Metric measurements.

    Worked Example

    Example: Footing Concrete 20 ft x 10 ft x 4 in

    STEPVALUE
    Convert depth4 in /12 = 0.333 ft
    Cubic feet20 x 10 x 0.333 = 66.67 ft3
    Cubic yards66.67 /27 = 2.47 yd3
    With 10% waste2.72 yd3

    Construction Information

    Material: Footings 8–12 in thick, walls 8 in. Concrete 3000–4000 psi. Footing below frost line per local code.

    • Measure longest x widest; split L-shapes into two rectangles and add.
    • Compact subgrade — soft spots add thickness.
    • For structural sizing (beams, headers, rebar) verify with a professional per local code.

    Material Information

    Footings 8–12 in thick, walls 8 in. Concrete 3000–4000 psi. Footing below frost line per local code.

    Waste & Overages

    Add 10% for over-excavation and slough — trench sides cave.

    Practical Tips

    • Call 811 before digging
    • Keep footings on undisturbed soil or compacted fill

    Common Mistakes

    • Shallow footings above frost line — heave
    • Not adding extra for footing flares

    Assumptions & Engineering References

    • Rectangular sections of uniform thickness. Split irregular shapes into non-overlapping rectangles.
    • Thickness and reinforcement must come from project plans; volume alone does not establish load capacity.

    This calculator provides an estimate based on your inputs. Actual requirements vary by site, material and installation. For code-regulated or load-bearing work, consult a qualified professional.

    Calculations run 100% in your browser — zero tracking of your dimensions or input data.

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    Frequently asked questions

    What does the Footing Concrete Calculator calculate?

    The Footing Concrete Calculator estimates footing concrete quantity for US jobs — Footing volume in cubic yards, Foundation wall area and concrete, Excavation volume with waste. Enter dimensions, choose units, add waste and price to get instant results.

    How do I measure for footing concrete?

    Measure footing concrete 20 ft x 10 ft x 4 in on site. Use the unit selectors — the tool converts inches→feet (÷12) and yards→feet (×3) before math. For non-rectangular, split into rectangles and add.

    How much waste should I add?

    Add 10% for over-excavation and slough — trench sides cave.

    How accurate is this footing concrete estimate?

    Math is exact for your inputs. Actual needs vary by site, material and installation. Add 5–10% waste for rectangular, 10–15% for irregular.

    About Calculator Street

    Built by Vipul Otari for US homeowners & contractors. Calculator inputs are processed in your browser. Estimates depend on your measurements, product specifications and the assumptions shown on this page. Confirm order quantities with your supplier and structural requirements with your project designer. Page updated: 2026-09-11.

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