Calculate concrete and rebar needed for continuous footings and pier footings. Get accurate material quantities, cost estimates, and ensure your foundation project starts on solid ground.
Enter your footing dimensions and click Calculate to see results
Concrete footings are the critical foundation elements that support structures by distributing loads to the soil. Properly calculated and installed footings prevent settling, cracking, and structural failure. Our Concrete Footing Calculator helps you determine exact material quantities for both continuous and pier footings.
Continuous Footings (Strip Footings): These run continuously under load-bearing walls, distributing the weight along the entire length. They're the most common type for residential foundations, supporting exterior and interior bearing walls. Typical dimensions are 16-24 inches wide and 8-12 inches thick, extending below the frost line.
Pier Footings (Spot Footings): These are isolated concrete pads placed under posts, columns, or concentrated loads. Common for decks, pole barns, pergolas, and structures where loads are concentrated at specific points rather than distributed along walls. Typically circular with diameters of 12-24 inches.
Footing dimensions must be calculated based on soil bearing capacity and structural loads:
Concrete bags come in two standard sizes, each yielding different amounts when mixed:
We recommend 80lb bags for footing projects as they're more economical ($5-8 each vs $4-6 for 60lb bags) and require fewer bags to mix, saving time and labor. For large projects (1+ cubic yards), consider ready-mix concrete delivered by truck at $100-150 per cubic yard.
Concrete is strong in compression but weak in tension. Rebar (steel reinforcing bar) provides tensile strength, preventing cracks from spreading:
Always add a waste factor to your concrete calculations to account for:
Use 5-7% waste for experienced contractors, 10% for DIYers. Running out of concrete mid-pour creates cold joints that weaken the footing, so it's always better to have slightly too much than not enough.
The frost line is the deepest level at which soil freezes in winter. Footings must extend below this depth to prevent frost heaving, which occurs when frozen ground expands and lifts structures:
Always check your local building code for specific frost depth requirements in your area. Building departments have exact specifications based on historical weather data.
Concrete footing costs vary based on several factors:
“Planning to build a deck and needed to calculate concrete for 8 pier footings. This calculator made it incredibly easy to determine exactly how many bags to buy and how much rebar I needed. Saved me a trip back to the store by getting the quantities right the first time. The cost estimate helped me budget the project perfectly.”
“I use this calculator for quick estimates on residential footing jobs. It's accurate, fast, and helps me provide clients with material costs on the spot. The ability to calculate both continuous and pier footings makes it versatile for different projects. The export feature is great for creating material lists for my crew.”
“Building a 12x16 storage shed and needed footings for the corners. This calculator helped me figure out I needed 6 bags of 80lb concrete per pier - way easier than trying to do the math myself! The rebar calculations were a bonus I didn't expect. Everything worked out perfectly and my shed is rock solid.”
Love using our calculator?
Dive deeper with our expert guides and tutorials related to Concrete Footing Calculator