How Much Concrete for a 10-Inch Round Footing 36 Inches Deep?
Material and bag counts for a 10" diameter × 36" deep round footing — cubic feet, cubic yards, and bag totals.
Estimate concrete for a 10" round sonotube footing 36" deep: exact volume 1.6362 cu ft (0.0606 yd³), plus planning numbers with 10% waste and bag counts for 40-, 60-, and 80-lb mixes.
This is a narrow tube-form pour: a 10" diameter × 36" deep round footing that contains 1.6362 cubic feet of concrete. It’s the kind of small, single-cylinder pour you order material for rather than schedule a big truck for.
That 36" deep tube often shows up under isolated posts or narrow column layouts. Plan on the listed bag counts if you’re using bagged concrete, and allow a little extra for waste or adjustments at the pour.
Quick Answer
Exact volume: 1.6362 cubic feet (0.0606 cubic yards).
Planning with 10% waste: 1.7998 cubic feet (0.0667 cubic yards). Planning bag counts: 6 40-lb bags, 4 60-lb bags, or 3 80-lb bags.
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How to Use This Footing Estimate
Quick steps to estimate and order for this 10" × 36" round footing.
- Measure the finished tube depth and diameter to confirm 36" deep and 10" diameter.
- Check the exact volume: 1.6362 cu ft per footing.
- Add the waste allowance (10%) to get 1.7998 cu ft for ordering.
- Decide material form: bags of concrete mix for a single pour, or ready-mix for several footings.
- If pouring multiple footings, multiply the planning volume and bag counts before buying.
- Round up bag counts to whole bags and keep an extra bag or two on hand.
Formula
Use this round footing formula:
Volume (ft³) = π × Radius (ft) × Radius (ft) × Depth (ft)
3.1416 × 0.42 × 0.42 × 3 = 1.64 ft³
1.64 ÷ 27 = 0.06 yd³
If you add a 10% waste allowance, you should plan closer to 0.07 cubic yards.
Worked Example
Single-footing example: the exact volume is 1.6362 cu ft (0.0606 yd³). With 10% waste that becomes 1.7998 cu ft (0.0667 yd³). Exact bag counts for one footing are 6 40-lb, 4 60-lb, or 3 80-lb; planning counts with waste are the same here.
Multiple-footing example: four identical footings total 6.5448 cu ft (0.2424 yd³) before waste. With 10% waste that’s 7.1992 cu ft (0.2668 yd³). Planning bag totals for four footings: 24 40-lb bags, 16 60-lb bags, or 12 80-lb bags.
Bag Count Estimate
- 3 bags of 80 lb concrete mix
- 4 bags of 60 lb concrete mix
- 6 bags of 40 lb concrete mix
Always verify the actual yield on the product label before buying materials.
When Bagged Concrete vs Ready-Mix Makes Sense
For a single 10" × 36" footing, bagged concrete is usually simpler. You can mix a handful of 40-, 60-, or 80-lb bags on site and finish the small pour without a truck. The listed bag counts (6/4/3) fit one footing with the 10% allowance.
If you’re doing several of these footings, ready-mix starts to make sense once the total volume approaches a truck minimum or when you want to save on mixing time. For a handful of footings, though, bagged concrete still often wins for simplicity and fewer logistics.
Common Uses for This Footing Size
This 10" diameter by 36" deep footing works well where a narrow cylindrical footing layout makes sense: isolated post supports, pergola posts, small deck or porch posts, sign supports, or similar single-point loads. The small footprint is geared toward situations needing a limited bearing area per support.
Actual suitability depends on load magnitude, soil bearing capacity, frost depth, and whether the footing needs reinforcement. These factors determine whether a 10" tube at 36" deep is sufficient or whether a larger diameter, deeper footing, or added rebar is required.
Common Mistakes to Avoid
Avoid these common estimating and planning mistakes for a 10" round footing.
- Forgetting to confirm finished depth and using excavation depth instead of the tube depth.
- Mixing up diameter and radius when checking the formula.
- Ordering exact bags only and not accounting for the 10% waste reserve.
- Rounding bag counts down instead of up; always buy whole bags.
- Failing to multiply volumes and bags correctly when ordering for multiple footings.
- Assuming ready-mix is cheaper without checking total volume and minimum delivery size.
Frequently Asked Questions
What is the exact concrete volume for a 10" round footing 36" deep?
The exact volume is 1.6362 cubic feet, which is 0.0606 cubic yards.
How many bags of concrete do I need for one 10" × 36" footing?
Exact bag counts for one footing are 6 40-lb bags, 4 60-lb bags, or 3 80-lb bags; use the planning counts with waste if you want a 10% buffer (the listed planning counts are the same here).
Why include a 10% waste allowance and how much is that for this footing?
A 10% waste allowance covers spillage, slight over-depth, and measurement variation. For this footing it raises the order quantity from 1.6362 cu ft to 1.7998 cu ft (0.0606 yd³ to 0.0667 yd³).
Is a 10" diameter × 36" deep footing adequate for a deck or pergola post?
A 10"×36" footing is sometimes used for isolated post supports, but adequacy depends on the post load, soil bearing capacity, frost depth, and reinforcement. Verify those factors before assuming this size is sufficient.
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.