Concrete footing material estimator
Concrete Footing Calculator
Estimate concrete volume, bags, ordering allowance and material cost for round pier holes or square pad footings.
Formula reviewed against the QUIKRETE calculator and residential concrete guidanceUpdated
Project inputs
Calculate concrete footings
Example layouts
Results
Concrete to order
Recommended purchase
Material estimate only
This calculator estimates quantity and bag cost. It does not size footings, reinforcement, frost protection, soil bearing capacity, post connections or structural loads. Follow the approved plan and local requirements.
Transparent math
How the footing estimate is calculated
- 1Find the volume of one footing
- 2Add the footings and ordering allowance
- 3Convert volume into bags
Reference notes
What to confirm before buying
Hole or pad dimensions
Measure the actual excavation or form dimensions. Round holes use diameter; square footings use the finished width.
Bag yield
Bag coverage varies by product and package size. Use the yield on the current product label instead of relying on a generic bag count.
Footing design
Depth, width, reinforcement and soil requirements are site and code decisions. This page only estimates concrete quantity after those dimensions are known.
Common planning questions
Concrete footing calculator FAQ
How do I calculate concrete for round footings?
Convert the diameter and depth to the same unit, calculate π x radius squared x depth for one footing, multiply by the footing count, then add the chosen allowance.
How many bags of concrete do I need for post holes?
Divide the order volume by the bag yield printed on the product. Round up to full bags and confirm the yield because 50 lb and 80 lb products do not cover the same volume.
Does this calculator design a footing?
No. It estimates concrete after you know the footing dimensions. Soil, loads, frost depth, reinforcement and local code determine the design.
Should I use ready-mix or bags?
Use bags for smaller jobs when the product yield and mixing plan are practical. For larger volumes, compare a ready-mix quote, delivery minimum and placement access with the bag estimate.