How to use it
- Enter the footing length in feet.
- Enter the width in feet.
- Enter the thickness in inches.
- Click calculate to see cubic yards, bags, and cubic feet.
This calculator lets you input the length, width, and thickness of a deck footing and instantly tells you how much concrete you’ll need in three useful units. Knowing the volume in cubic yards helps you compare quotes from suppliers, while the bag count translates directly to how many 80‑lb sacks to order. The cubic‑feet figure is handy for on‑site checks and for estimating waste. The tool uses the standard conversion that one 80‑lb bag yields about 0.6 ft³, so you get realistic numbers without guesswork. Just enter the dimensions, hit calculate, and read the three results—cubic yards, bags, and cubic feet—so you can budget, order, and avoid costly over‑or under‑purchases. You can also adjust for a 5% waste factor if you expect spillage, and the results update instantly. This makes planning for a new patio, a raised garden bed, or a repair job quick and accurate.
Pro tips
- Add a 5% waste allowance to cover spillage and over‑fill.
- Round up the bag count to the next whole bag to ensure you have enough.
- Order an extra bag or two in case of mix errors or future repairs.
- Double‑check that thickness is entered in inches, not feet.
Real-life examples
- A homeowner estimating concrete for a new deck’s footings.
- A contractor preparing a bid for a patio foundation.
- A DIY gardener building raised beds with concrete footings.
Case study
Mike entered a 12 ft × 8 ft footing 6 in thick and the calculator returned 1.78 cubic yards, 84 bags, and 48 cubic feet. He ordered 85 bags, saved a day on site, and avoided the cost of an extra delivery.