How to use it
- Enter the footing diameter (in), depth (ft) and quantity
- Click the Calculate button
- Read the cubic yards, 80‑lb bag count, and cubic feet results
The Concrete Footing Calculator turns three simple measurements—diameter, depth, and quantity—into the exact volume of concrete you’ll pour. It outputs three practical units: cubic feet for on‑site verification, cubic yards for contractor quotes, and the number of 80‑lb bags you must purchase. Knowing these numbers before you order prevents costly over‑orders and avoids running short mid‑project. The tool uses the standard conversion that one 80‑lb bag yields 0.6 cubic feet, and 27 cubic feet equal one cubic yard, so the results are directly tied to real‑world material sizing. Read the cubic‑yard figure to discuss pricing with a supplier, use the bag count to place your order, and keep the cubic‑foot total as a quick check against the excavation depth of the project.
Pro tips
- Add a 10% waste allowance to the bag count
- Always round up the number of bags, never down
- Order a few extra bags to cover unexpected variations
- Double‑check depth measurements before entering them
Real-life examples
- Estimating concrete for a new deck footings
- Sizing material for fence post footings
- Planning the foundation footings of a small shed
Case study
Mike needed footings for a 12‑ft deck. He entered a 12‑in diameter, 2‑ft depth, and 6 footings. The calculator showed 0.44 cubic yards, 7 bags, and 12 cubic feet, so he ordered 8 bags and avoided a second delivery, saving time and $120.