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Concrete Footings Calculator

Estimates the concrete volume for footings from the run length in feet and the trench width and depth in inches, returning cubic yards and cubic feet.

What this calculator does

The Concrete Footings Calculator estimates your result instantly from the values you enter, using standard construction & home formulas. Estimates the concrete volume for footings from the run length in feet and the trench width and depth in inches, returning cubic yards and cubic feet. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.

Concrete Footings Calculator

Result

—
Concrete Needed (yd³)
—
Cubic Feet

About Concrete Footings Calculator

Footings are usually long and narrow, so this calculator takes the run length in feet and the trench width and depth in inches. That mix of units matches how footings are actually dimensioned.

It returns the concrete volume in cubic yards and cubic feet so you can order the right amount of ready-mix.

Formula & Mathematical Calculation

Concrete Needed (yd³) = f(Footing Length (ft), Width (in), Depth (in))

Calculated according to standard construction formulas implemented in the calculator core.

Calculation Example

For a 30 ft footing 16 in wide and 8 in deep: volume = 30 × (16 ÷ 12) × (8 ÷ 12) = 26.67 ft³.

Cubic yards = 26.67 ÷ 27 = 0.99 yd³. The calculator shows 0.99 yd³ and 26.67 ft³.

Key Benefits

  • Handles the mixed units footings use: length in feet, width and depth in inches.
  • Reports concrete in both cubic yards and cubic feet.
  • Uses the exact 27 cubic feet per cubic yard conversion.
  • Gives a clear volume to quote when ordering ready-mix concrete.

How to Use this Calculator

  1. Enter the footing length
    Type the footing run length in feet into the Footing Length (ft) field.
  2. Enter the width
    Type the trench width in inches into the Width (in) field.
  3. Enter the depth
    Type the trench depth in inches into the Depth (in) field.
  4. Calculate
    Select Calculate to compute the volume.
  5. Read the results
    Read Concrete Needed in cubic yards and the Cubic Feet total in the result boxes.

Assumptions & Limitations

What the calculation assumes

  • Every value you enter is treated as an exact, known amount.
  • Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
  • Results use standard published formulas and account only for the values entered above.
  • Rounding is applied for display; the underlying calculation uses your full precision.
  • Results are returned in the same units you enter, unless the tool states the output unit.

What it does not cover

  • Concrete Footings Calculator produces a calculated result for reference and learning, not a certified or official measurement.
  • Real-world outcomes differ when tolerances, rounding rules or local standards apply.
  • Definitions and standards vary by region and change over time; verify the convention that applies to your case.
  • Figures are only as accurate as the inputs you supply — check them before acting on the result.
  • For work where the result carries real consequences, confirm it against an authoritative source.

Frequently Asked Questions

Footings are long relative to their cross-section, so their width and depth are usually measured in inches. The calculator converts both to feet by dividing by 12 before finding the volume.

The volume in cubic feet is divided by 27, because one cubic yard contains 27 cubic feet.

It computes one continuous run. For separate footings, total their lengths or run the calculation for each and add the volumes.

No. The result is the exact calculated volume, so add your own margin for over-excavation or spillage.

Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.