Footing planning checklist
Use this calculator for a straight rectangular foundation footing, wall footing, or strip footing. It estimates the concrete for the measured trench length, width, and depth. Calculate stepped sections, pier enlargements, and other non-rectangular changes as separate pours.
Confirm the actual excavation dimensions
Footing plans show intended dimensions, but the trench is what receives the concrete. Measure or confirm the width and depth after excavation, especially where soil has fallen in or the trench was over-dug.
Check frost depth and engineering notes
Frost depth, bearing conditions, reinforcement, and footing size may be controlled by local code or the project design. This calculator estimates volume; it does not determine the required footing dimensions or replace project-specific guidance.
Why the default footing waste is 8%
Excavated trenches are rarely perfect. Loose edges, rounded corners, uneven bottoms, and cleanup can increase the true concrete volume, so the default is higher than the simple slab allowance. Adjust it once the actual site conditions are known.
Footing concrete cost estimate
Use the ready-mix price or 60 lb bag price fields to compare basic material cost estimates. The result includes the selected waste allowance, while actual project cost may also include delivery, short-load fees, rebar, gravel, forms, labor, and excavation.
Example footing projects
A small wall footing or short foundation trench.
A longer continuous footing where ready-mix may be more practical.
A larger footing that should be checked against actual excavation dimensions.
Footing calculator FAQ
How much concrete do I need for a footing?
Enter the footing length, width, depth, and number of footings. The calculator shows the net volume, adds your waste allowance, and gives the total concrete needed.
How much does footing concrete cost?
Enter local ready-mix and 60 lb bag prices to compare basic material cost estimates. Delivery, short-load fees, labor, rebar, gravel, forms, and excavation are separate costs.
How much waste should I add to a concrete footing?
The calculator starts at 8%. Increase the allowance when trench edges are loose, the bottom is uneven, or the excavation is likely to be over-dug.
Need help measuring a footing?
See the worked volume example, waste guidance, and pre-order checklist.