Concrete Footing Calculator
Concrete footings support the foundation of structures. This calculator handles both continuous strip footings and isolated pad footings. Enter dimensions to get cubic yards of concrete, bag counts, and linear feet of rebar needed.
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How to Use This Calculator
- 1Enter your measurements in the fields above. Use the units shown next to each field (ft, in, etc.).
- 2Click Calculate to get your material estimate instantly.
- 3Review the highlighted result — it shows the key quantity you need to order.
- 4Use Copy Results to save your estimate, or bookmark the URL — your inputs are encoded in the link.
Pro tip: Always add 10% to your material order to account for waste, cuts, and defects.
Frequently Asked Questions
How deep should a concrete footing be?
Footings must extend below the frost line in your area to prevent heaving. In the northern US, frost depth is 36–48 inches. In the South, 12–18 inches is often acceptable. Check your local building code for the required depth.
What is the minimum width for a concrete footing?
The minimum footing width is typically twice the wall thickness above it. For an 8-inch concrete block wall, use a 16-inch-wide footing. Footings also must be as deep as they are wide (minimum) and at least 6 inches deep.