How Much Concrete for a 24-Inch Round Footing 24 Inches Deep?
24" diameter × 24" deep round footing: concrete volume, cubic yards, and bag counts for this exact pour.
Exact material numbers for a 24" diameter by 24" deep round Sonotube footing: 6.2832 cu ft (0.2327 cu yd) and bag planning with a 10% waste allowance included.
At 24 inches deep this is a narrow, low-volume round pour using a tube form. The footing measures 24" diameter × 24" deep and comes out to a small, manageable volume for a single pour.
This size is often used for isolated post supports or similar single-point loads. Expect shallow excavation (24" deep), simple form setup, and that bagged concrete will cover most single-footing jobs unless you’re pouring several at once.
Quick Answer
Exact volume: 6.2832 cubic feet (0.2327 cubic yards).
Planning with 10% waste: 6.9115 cu ft (0.256 cu yd). Planning bag counts: 24 40-lb bags, 16 60-lb bags, or 12 80-lb bags (waste-adjusted).
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How to Use This Footing Estimate
Quick steps to estimate and plan for a 24" round footing at 24" deep.
- Measure the finished diameter and depth: 24" diameter × 24" deep for this page.
- Confirm the exact volume: use the cylinder formula or the provided value 6.2832 cu ft.
- Add waste allowance: use 10% here to get 6.9115 cu ft for ordering.
- Decide materials: bagged concrete is simplest for a single footing; ready-mix is worth comparing for multiple footings.
- If you have more than one footing, multiply the planning volume and bag counts before ordering.
- Round up bag counts to whole bags and factor delivery or pickup timing into purchase plans.
Formula
Use this round footing formula:
Volume (ft³) = π × Radius (ft) × Radius (ft) × Depth (ft)
3.1416 × 1 × 1 × 2 = 6.28 ft³
6.28 ÷ 27 = 0.23 yd³
If you add a 10% waste allowance, you should plan closer to 0.26 cubic yards.
Worked Example
Single-footing example: exact volume before waste is 6.2832 cu ft (0.2327 cu yd). Exact bag counts for the single pour are 21 40-lb bags, 14 60-lb bags, or 11 80-lb bags. With 10% waste the planning volume is 6.9115 cu ft (0.256 cu yd) and planning bags are 24 40-lb, 16 60-lb, or 12 80-lb.
Multiple-footing example (4 footings): total exact volume = 25.1328 cu ft, total exact = 0.9308 cu yd. Exact bags total 84 40-lb, 56 60-lb, or 44 80-lb. With 10% waste the planning totals are 27.646 cu ft (1.024 cu yd) and 96 40-lb, 64 60-lb, or 48 80-lb bags.
Bag Count Estimate
- 12 bags of 80 lb concrete mix
- 16 bags of 60 lb concrete mix
- 24 bags of 40 lb concrete mix
Always verify the actual yield on the product label before buying materials.
Bag Counts by Waste Buffer for 24" diameter × 24" deep
Pick a buffer based on site conditions: clean forms and accurate measurements can run leaner; rough subgrade or hard-to-reach pours need more cushion.
| Buffer | Volume (ft³) | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|
| No buffer | 6.28 | 11 | 14 | 21 |
| +5% typical DIY | 6.6 | 11 | 15 | 22 |
| +10% recommended | 6.91 | 12 | 16 | 24 |
| +15% rough conditions | 7.23 | 13 | 17 | 25 |
When Bagged Concrete vs Ready-Mix Makes Sense
Bagged concrete is often simpler for this single 24" × 24" footing. You can buy 24 40-lb bags (waste-adjusted) and mix on site without waiting for a truck, and mixing one or two small batches is straightforward.
If you have several footings to pour the math changes. Once you hit multiple footings (three or more) the total volume and handling time can make ready-mix worth pricing out, because it reduces on-site mixing and time spent shuttling bags.
Common Uses for This Footing Size
This 24" diameter by 24" deep footing fits isolated post supports where a narrow cylindrical layout makes sense, such as a pergola post, a deck corner post, a small sign base, or similar single-point supports. The footprint is compact and the pour volume is small enough to handle with bagged concrete for one or two footings.
Actual suitability depends on the load being carried, the soil bearing capacity, frost depth at the site, whether reinforcement is needed, and local permit requirements. For heavier loads or questionable soils you’ll want design input from an engineer or the building department before finalizing footing size or reinforcement.
Common Mistakes to Avoid
Common estimating and ordering mistakes for this footing size.
- Using the diameter instead of the radius in the formula.
- Forgetting to add the 10% waste allowance before ordering bags.
- Mixing bag counts and planning counts—order the waste-adjusted numbers, not the exact counts.
- Rounding bag counts down instead of up and arriving short during the pour.
- Not multiplying volumes and bag counts correctly when ordering for multiple footings.
- Assuming ready-mix is cheaper than bags without comparing total time and delivery costs.
Frequently Asked Questions
What is the exact concrete volume for a 24" round footing 24" deep?
The exact calculated volume is 6.2832 cubic feet, which equals 0.2327 cubic yards.
How many bags of concrete do I need for this single footing?
Exact bag counts for the single footing are 21 40-lb bags, 14 60-lb bags, or 11 80-lb bags. For ordering with a 10% waste allowance use 24 40-lb, 16 60-lb, or 12 80-lb bags.
Why add a 10% waste allowance and how much is that here?
The 10% allowance covers spillage, slight over-excavation, and minor measurement differences. For this footing it increases the volume from 6.2832 cu ft to 6.9115 cu ft (0.256 cu yd) for ordering.
Is a 24" diameter by 24" deep footing adequate for my post or pergola support?
A 24" × 24" footing may work in some cases, especially for small, isolated posts. Whether it’s adequate depends on the actual load, soil bearing capacity, frost depth, and whether reinforcement is required; consult a structural engineer or building official if you’re unsure.
Keep Planning Your Concrete Project
Use the calculator, compare more footing pages, and review your estimate before buying materials.
Disclaimer: This page provides planning estimates only. Actual concrete needs vary with excavation accuracy, site conditions, local code requirements, bag yield, and supplier guidance. Always verify measurements before buying materials, and consult a qualified professional for structural or code-sensitive work.