Footing Calculator
Enter total footing length in feet plus width and depth in inches to get the concrete volume in cubic yards and cubic feet. The inch measurements are converted to feet first.
What this calculator does
The Footing Calculator estimates your result instantly from the values you enter, using standard construction & home formulas. Enter total footing length in feet plus width and depth in inches to get the concrete volume in cubic yards and cubic feet. The inch measurements are converted to feet first. 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.
Result
About Footing Calculator
A continuous footing is a long trench of concrete under a wall or foundation. This calculator treats it as a rectangular prism: total length in feet times the cross-section width and depth, both entered in inches and converted to feet.
The volume comes out in cubic feet as length × (width ÷ 12) × (depth ÷ 12), and dividing by 27 gives cubic yards for ordering ready-mix.
Formula & Mathematical Calculation
Concrete (yd³) = f(Total Length (ft), Width (in), Depth (in))
Calculated according to standard construction formulas implemented in the calculator core.
Calculation Example
For 120 ft of footing, 20 in wide and 10 in deep:
- Cubic feet = 120 × (20 ÷ 12) × (10 ÷ 12) = 120 × 1.667 × 0.833 = 166.7 ft³
- Cubic yards = 166.667 ÷ 27 = 6.17 yd³
The tool shows Concrete 6.17 yd³ and Cubic Feet 166.7.
Key Benefits
- Converts inch width and depth to feet automatically for the volume math
- Handles the full run of footing from a single total-length entry
- Reports both cubic yards and cubic feet for ordering concrete
- Free, runs in your browser, with no sign-up
How to Use this Calculator
-
Enter the total length
Type the combined length of the footings in feet into the Total Length (ft) field, such as 120. -
Enter the width
Type the footing width in inches into the Width (in) field, such as 20. -
Enter the depth
Type the footing depth in inches into the Depth (in) field, such as 10. -
Calculate
Press Calculate to see the concrete volume in cubic yards and cubic feet.
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
- Footing 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
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.