Concrete Footing Cost Calculator
Figure the cubic yards of concrete in a footing from its length, width and depth, then apply your price per cubic yard for a planning-estimate total.
Calculator
A 120 ft footing at 16×8 in is 3.95 cubic yards of concrete ≈ $651.85 at $165.00/cu yd. Footing size and rebar are engineered — confirm with a pro and pull a permit.
A footing is the widened concrete base that spreads a wall or column load onto the soil — the strip beneath a foundation wall, the pads under posts and piers, the trench footing for a retaining wall. Unlike a flat slab, it is a long prism: you know its length in feet and its cross-section (width and depth) in inches. This calculator converts that into cubic yards of concrete and multiplies by the delivered price you enter, so you can budget the pour and order the right amount of ready-mix.
Enter the total run of footing, its width and its depth, and your price per cubic yard. The tool returns the volume and cost. As with every calculator here, there is no price list inside — the per-yard figure is yours, from your quote — and the geometry is timeless, so the result never needs updating. What the tool does not do is size the footing: that is engineering, covered in the notes.
Formula
A footing is length times cross-section, converted to cubic yards, then priced:
volume_cu_yd = linear_ft × (width_in ÷ 12) × (depth_in ÷ 12) ÷ 27\ncost = volume_cu_yd × price_per_cuyd
Width and depth are converted from inches to feet (each ÷ 12), multiplied by the length in feet to get cubic feet, then divided by 27 to reach cubic yards. It is the same /27 cubic-yard math as a slab, just with a rectangular cross-section instead of a thickness. Add the usual 5–10% when you order, since a hand-dug trench is never a perfect rectangle and over-dig fills with concrete.
Worked example
A 120 ft foundation footing, 16 inches wide and 8 inches deep, with ready-mix quoted at $165 per cubic yard:
- Volume = 120 × (16 ÷ 12) × (8 ÷ 12) ÷ 27 = 3.95 cu yd
- Concrete = 3.95 × $165 = $651.75
Widen the footing to 20 inches and the volume climbs to about 4.94 cubic yards — roughly a quarter more concrete — because volume is linear in the cross-section. Footing dimensions are set by the load and the soil, not chosen to save concrete, which is exactly why the sizing belongs to an engineer.
What a footing does, and why it is engineered
A footing exists to spread load. A foundation wall might carry a heavy line load, but soil can only bear so much pressure; the footing widens the base so the load per square foot on the soil stays within safe limits. That is why footing width and depth are not arbitrary — they follow from the load above and the bearing capacity of the soil below, and they are commonly set by code minimums for typical houses or by an engineer for anything unusual. This tool takes those dimensions as inputs and prices the concrete; it does not tell you how wide or deep the footing should be.
Reinforcement and depth add cost the volume math does not show. Most footings carry rebar, tied and placed before the pour, and the price of steel and the labor to set it are separate from the concrete. Footings must also sit below the local frost line so they do not heave in winter, which in cold regions means digging deeper trenches — more excavation, and sometimes more concrete in a stepped footing on a slope. Budget rebar, excavation and any stepping as extra lines alongside the concrete figure here.
Footings are structural, and structural work needs a licensed professional, a permit and an inspection. The size, the reinforcement, the depth to stable and non-frost-susceptible soil, and the bearing check are engineering decisions — have a licensed structural or geotechnical engineer confirm them and pull the permit before you pour. Use the output as a planning estimate for budgeting and ordering ready-mix, never as a design or a bid.