How Much Concrete for a 22x22x24 Footing?
Exact volume and planning bag counts for a 22" x 22" x 24" footing in cubic feet and yards.
Get the precise concrete volume and bag plan for a 22" x 22" x 24" footing. Includes cubic feet, cubic yards, waste-adjusted planning volumes, and recommended bag counts for 40-, 60-, and 80-lb bags.
This footing is 24" deep, which often matters more than the surface footprint when you dig and prepare the hole. At 22" by 22" and 24" deep you should plan for a deeper excavation, proper base compaction, and any shoring needed to keep the sides stable during work.
Because the depth is substantial relative to the width, expect extra labor for excavation and a closer look at reinforcement. This size can work for heavy deck posts or small columns where the 24-inch depth meets local frost-depth or bearing requirements and the soil supports the load.
Quick Answer
Exact volume for one 22" x 22" x 24" square footing is 6.7222 cubic feet, which converts to 0.249 cubic yards. With a 10% waste allowance the planning volume becomes 7.3944 cubic feet, or 0.2739 cubic yards.
Exact bag counts for this single footing are 23 40-lb bags, 15 60-lb bags, or 12 80-lb bags. For planning with 10% waste use 25 40-lb bags, 17 60-lb bags, or 13 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 workflow to pour this footing:
- Mark the location and cut or stake out a 22" by 22" square on the ground.
- Excavate straight down to 24" deep and remove loose soil, then compact the base or add a gravel pad if specified.
- Place formwork if required and set any reinforcement (rebar or wire) per engineer instructions.
- Mix bagged concrete or arrange a small ready-mix delivery and pour the concrete into the form or hole.
- Consolidate with a rod or tamp, strike off the top, and finish the surface as needed.
- Keep the concrete damp and protected while it cures for at least several days per mix recommendations.
Formula
The basic formula is length × width × depth to get cubic feet, then divide by 27 to convert cubic feet to cubic yards. For this square footing length and width are 1.8333 ft each and depth is 2 ft.
Area = 1.8333 ft × 1.8333 ft = 3.3611 sq ft. Volume (cubic feet) = area × depth = 3.3611 sq ft × 2 ft = 6.7222 cu ft. Convert to cubic yards: 6.7222 cu ft ÷ 27 = 0.249 yd³.
Apply the default waste allowance of 10%: planning volume = 6.7222 cu ft × 1.10 = 7.3944 cu ft, which equals 7.3944 ÷ 27 = 0.2739 yd³ for ordering or bag counts.
Worked Example
Single-footing example: one footing is 6.7222 cubic feet of concrete, or 0.249 cubic yards. With 10% waste plan on 7.3944 cubic feet, or 0.2739 cubic yards, and about 25 40-lb bags (or 17 60-lb bags / 13 80-lb bags) to be safe.
Multiple-footing example: three identical footings require 3 × 6.7222 = 20.1666 cubic feet total, which is 0.747 cubic yards. With 10% waste plan on 3 × 7.3944 = 22.1832 cubic feet, or 0.8217 cubic yards; that equates to roughly 75 40-lb bags, 51 60-lb bags, or 39 80-lb bags when you multiply the per-footing planning counts.
Bag Count Estimate
- 13 bags of 80 lb concrete mix
- 17 bags of 60 lb concrete mix
- 25 bags of 40 lb concrete mix
Always verify the actual yield on the product label before buying materials.
Bag Counts by Waste Buffer for 22" x 22" x 24"
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 | 6.72 | 12 | 15 | 23 |
| +5% typical DIY | 7.06 | 12 | 16 | 24 |
| +10% recommended | 7.39 | 13 | 17 | 25 |
| +15% rough conditions | 7.73 | 13 | 18 | 26 |
When Bagged Concrete vs Ready-Mix Makes Sense
For a single 22" × 22" × 24" footing the planning volume is only 0.2739 cubic yards. That small quantity makes bags of concrete mix practical and cost-effective: you can buy exactly 25 40-lb bags (planning count) and mix where you work without a truck. Bags also let you stage the pours if you have multiple footings and limited access for a mixer or truck.
Ready-mix is faster on-site and gives consistent results, but many suppliers have minimum delivery volumes and extra fees for very small loads. For this footing the total is under a cubic yard, so compare supplier minimums and costs; for multiple footings or where labor is limited, ready-mix may still be worth arranging despite the small per-footing volume.
Common Uses for This Footing Size
A 22x22x24 footing is commonly used for supporting single posts in residential projects. You might see it under deck posts, pergola posts, fence posts, or small porch columns. Its size fits well for these types of supports where the load isn’t too heavy and the post is fairly standard in size. This footing helps keep posts stable in typical backyard or light-duty outdoor structures.
Whether this footing size is right depends on several factors. The weight the post will carry, the type of soil, how deep the footing needs to go to avoid frost, and if any reinforcement is needed all play a role. Local building codes also affect what footing size you should use. It’s important to consider these details before deciding on this footing size for your project.
Common Mistakes to Avoid
Common pitfalls to avoid when building this footing:
- Underestimating excavation time and the effort to reach a firm, uncompacted base.
- Skipping reinforcement or using undersized rebar relative to the required structural design.
- Ordering only the exact bags without any waste allowance and running short on the pour day.
- Failing to compact or level the bottom, which can cause uneven bearing and settlement.
- Overwatering the mix to improve workability, which weakens the finished concrete.
- Not protecting the fresh concrete from rapid drying or cold temperatures during cure.
Frequently Asked Questions
How much concrete does one 22" x 22" x 24" footing need?
One footing requires 6.7222 cubic feet of concrete, which is 0.249 cubic yards. With a 10% waste allowance plan on 7.3944 cubic feet or 0.2739 cubic yards.
How many bags of concrete mix do I need for this footing?
Exact counts are 23 40-lb bags, 15 60-lb bags, or 12 80-lb bags. For planning with 10% waste use 25 40-lb bags, 17 60-lb bags, or 13 80-lb bags.
Why add a 10% waste allowance to the concrete volume?
The 10% allowance covers small overexcavation, slight variations in depth or dimensions, spillage, and rounding when using bagged mixes. It helps avoid coming up short on pour day.
Is a 22" x 22" x 24" footing large enough for a deck post?
It depends on the deck load, soil bearing capacity, reinforcement, and whether a 24-inch depth meets your local frost-depth and building-department requirements. Have the footing sized by a structural designer or follow your building department's guidance when in doubt.
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.