30 ft x 16 in x 8 in footing
- Cubic feet
- 29.3333333333
- 80 lb bags
- 49
- 60 lb bags
- 66
Footing size, reinforcement, soil bearing, frost depth, drainage, inspection rules, and local code need professional review.
Concrete Footing Calculator
Use this free concrete footing calculator to estimate cubic feet, cubic yards, and common concrete bag counts from footing length, width, depth, and waste.
Research-backed assumptions Formula steps Examples included Private in-browser use
Formula steps
- Convert footing width and depth from inches to feet.
- Multiply length by width by depth for cubic feet.
- Add waste, convert to cubic yards, and estimate common bag counts.
How to use the concrete footing calculator
- Enter footing length in feet, then width and depth in inches.
- Press Estimate footing to see cubic feet, cubic yards, and common concrete bag counts.
- Use cubic yards for ready-mix planning and bag counts for small hand-mix projects.
- Footing size, reinforcement, frost depth, soil, drainage, and code requirements need professional review.
Common uses
Estimate concrete for a simple straight footing run.
Convert width and depth in inches into cubic yards.
Compare ready-mix volume with common bag counts.
Add a realistic waste cushion before pricing material.
Examples
About 1.09 cubic yards
Concrete and bag estimate
Small-volume estimate
Frequently asked questions
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
When should I use the Concrete Footing Calculator?
Use it when your task matches one of these common needs: Estimate concrete for a simple straight footing run. Convert width and depth in inches into cubic yards. It works best when you already know the values, dates, units, or settings the page asks for.
What is the Concrete Footing Calculator doing with my inputs?
In plain language: The calculator converts footing width and depth from inches to feet, multiplies length by width by depth, adds waste, converts cubic feet to cubic yards, and rounds bag counts up. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
What do the main Concrete Footing Calculator inputs mean?
Footing length: the total straight run of the footing in feet. Width and depth: the footing cross-section in inches. Waste percent: extra concrete for uneven trenches, spillage, and a small ordering cushion. Bag counts: rounded estimates based on common dry-mix bag yields, useful for small jobs.
How should I read the Concrete Footing Calculator answer?
Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.
What should I double-check before trusting the answer?
Footing dimensions are structural decisions. Soil bearing, frost depth, reinforcement, drainage, inspections, and local code can change the real footing design. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.
Why does the Concrete Footing Calculator show both cubic yards and bags?
Cubic yards are useful for ready-mix orders, while 60 lb and 80 lb bag counts are useful for smaller hand-mixed projects. Large footings are usually better handled with a concrete supplier or contractor.
Can this tell me the correct footing size?
No. It only estimates material from the size you enter. The right footing size depends on loads, soil, frost depth, reinforcement, and building rules.
Does the site save what I enter?
No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.
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