How Much Concrete for a 24x24x48 Footing?
Volume and bag planning for a 24" x 24" x 48" footing — cubic feet, cubic yards and bag counts.
Find exact concrete volume (16 cu ft / 0.5926 yd³), waste-adjusted planning volume, and recommended bag counts for a 24×24×48 footing, plus pour steps and common pitfalls.
If you need a footing for a single column, post, or small support, the 24"×24"×48" size gives 16 cubic feet of concrete and a deep, stable bearing area. Depth and width make this footing useful for deck posts, light columns, and standalone support where deeper footing meets frost-depth concerns.
This page focuses on practical planning: the measured volume, how many bags of concrete mix to buy if you hand-mix, and when a ready-mix truck makes sense. Remember to consider reinforcement, local bearing capacity, and whether the 48" depth meets your local frost-depth requirements.
Quick Answer
Exact volume: 16.0 cubic feet, which is 0.5926 cubic yards. With a 10% allowance for waste and overage you should plan for 17.6 cubic feet total, or about 0.6519 cubic yards.
For planning, estimate about 59 40-lb bags, 40 60-lb bags, or 30 80-lb bags (these counts include the ~10% waste allowance). Exact counts without waste are 54 40-lb bags, 36 60-lb bags, or 27 80-lb bags.
Need a custom estimate? Use the Footing Calculator. Browse footing size pages. All project pages.
How to Use This Footing Estimate
Quick steps to plan and place concrete for this footing.
- Verify footing size: 24 in × 24 in × 48 in (2 ft × 2 ft × 4 ft).
- Calculate volume: multiply length × width × depth to get 16 cu ft, then add ~10% for waste to get 17.6 cu ft.
- Decide delivery method: bags for a single footing or ready-mix when pouring many footings.
- Prepare the hole, compact the bottom, add formwork and reinforcement (rebar or wire mesh) as required.
- Mix and place concrete, consolidate to remove voids, then finish and cure according to product instructions.
- Allow proper curing time before applying load—follow local code for timing and inspection.
Formula
The basic volume formula is length × width × depth. For this square footing that’s 2 ft × 2 ft × 4 ft = 16 cubic feet.
To convert cubic feet to cubic yards divide by 27: 16 cu ft ÷ 27 = 0.5926 cubic yards (rounded to four decimal places as supplied).
Include a waste factor to cover spillage, variations in excavation, and slight overpour. At 10% waste: 16 cu ft × 1.10 = 17.6 cu ft. In cubic yards that’s 0.5926 yd³ × 1.10 = 0.6519 yd³.
Worked Example
Example 1 — one footing: the total volume is 16.0 cubic feet (0.5926 yd³). With 10% waste you’ll order or plan for 17.6 cu ft (0.6519 yd³), which translates to about 59 40-lb bags, 40 60-lb bags, or 30 80-lb bags.
Example 2 — three identical footings: total concrete required is 3 × 16.0 = 48.0 cubic feet, which is 48.0 ÷ 27 = 1.7778 cubic yards. With 10% waste multiply totals by 1.10 for 52.8 cu ft (1.9556 yd³). For bag planning multiply single-footing planning bags by three (about 177 40-lb bags, 120 60-lb bags, or 90 80-lb bags).
Bag Count Estimate
- 30 bags of 80 lb concrete mix
- 40 bags of 60 lb concrete mix
- 59 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" x 24" x 48"
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 | 16 | 27 | 36 | 54 |
| +5% typical DIY | 16.8 | 29 | 38 | 57 |
| +10% recommended | 17.6 | 30 | 40 | 59 |
| +15% rough conditions | 18.4 | 31 | 41 | 62 |
When Bagged Concrete vs Ready-Mix Makes Sense
For one 24"×24"×48" footing bagged concrete is often the most convenient option: you can buy the number of bags you need, mix on-site, and finish the pour without waiting for a truck. Bagged mix is practical when the total volume is under about one cubic yard and when access or pump logistics make a truck impractical.
If you have several footings or want faster placement and more consistent batches, ready-mix can be more efficient. This footing requires about 0.6519 yd³ with waste — if you’re pouring multiple footings the cumulative yardage can justify a truck, reduce labor, and improve uniformity. Balance material cost, mixing time, and site access when choosing between bags and ready-mix.
Common Uses for This Footing Size
A 24x24x48 footing is commonly used for supporting deck posts, pergola posts, fence posts, and small porch columns. Its size fits well for single-point supports where the load isn’t too heavy. This footing can help keep these structures stable by distributing weight into the ground. It’s often chosen for residential projects where a straightforward, square footing is needed to hold up vertical posts.
Whether this footing size works depends on several factors like the weight it needs to carry, the type of soil, how deep the frost line is in your area, and if any reinforcement is necessary. Local building codes also play a role in deciding if this footing meets the requirements. It’s important to consider these details before choosing this footing size for your project.
Common Mistakes to Avoid
Common mistakes to avoid when planning and pouring this footing:
- Underestimating volume by skipping the waste allowance.
- Poorly compacted subgrade leading to settlement.
- Omitting required reinforcement or using undersized rebar.
- Overwatering the mix, which weakens strength.
- Not bracing forms adequately for vertical pressure.
- Failing to cure the concrete properly before applying load.
Frequently Asked Questions
How much concrete do I need for a 24x24x48 footing?
The footing requires 16.0 cubic feet of concrete, which is 0.5926 cubic yards. With a 10% waste allowance plan for 17.6 cubic feet or about 0.6519 cubic yards.
How many bags of concrete mix do I need for this footing?
Plan on approximately 59 40-lb bags, 40 60-lb bags, or 30 80-lb bags when you include a 10% waste allowance. Exact counts without waste are 54, 36, and 27 respectively.
Why should I add 10% waste to the calculated volume?
Adding about 10% covers spillage, slight over-excavation, form irregularities, and mixing variation. It helps avoid a shortfall mid-pour and reduces the risk of making a second trip for more material.
Is a 24x24x48 footing large enough for a deck post?
It can be suitable for a deck post in many situations, but suitability depends on the post load, soil bearing capacity, local frost depth, reinforcement, and code requirements. Confirm loads and local building department rules before relying on this footing size.
Keep Planning Your Concrete Project
Use the calculator, compare footing pages, and keep your estimate practical before you buy 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.