Post Hole Concrete Material Estimator
Estimate bagged concrete for fence, deck, sign, or small pier post holes before checking frost depth, code, drainage, utility locates, and post-base details.
Enter project values
Use the example values or enter your own project measurements.
Planning estimate only. Results update locally in your browser.
Plan the order
Compare waste, depth, thickness, and package assumptions before buying material.
Educational/planning estimate only. Confirm product labels, supplier rules, code requirements, site conditions, and contractor guidance where relevant.
What this means
12 post holes at 12 in diameter by 36 in deep need about 25.13 ft³ before waste, or 27.65 ft³ after a 10% buffer. That is roughly 1.02 yd³ (0.78 m³), 47 80 lb bags, or 62 60 lb bags. The post displacement removes about 3.14 ft³ from the concrete volume.
Material memo
Copy or print a local-only order note for your supplier, shopping list, or project plan.
| Hole diameter | Concrete ft³ | Concrete yd³ | Concrete m³ | 80 lb bags | 60 lb bags |
|---|---|---|---|---|---|
| 10 in | 18.14 | 0.67 | 0.51 | 31 | 41 |
| 12 in | 27.65 | 1.02 | 0.78 | 47 | 62 |
| 14 in | 38.88 | 1.44 | 1.1 | 65 | 87 |
- Concrete ft³
- 18.14
- Concrete yd³
- 0.67
- Concrete m³
- 0.51
- 80 lb bags
- 31
- 60 lb bags
- 41
- Concrete ft³
- 27.65
- Concrete yd³
- 1.02
- Concrete m³
- 0.78
- 80 lb bags
- 47
- 60 lb bags
- 62
- Concrete ft³
- 38.88
- Concrete yd³
- 1.44
- Concrete m³
- 1.1
- 80 lb bags
- 65
- 60 lb bags
- 87
Bag staging cue
47 80 lb bags is the headline buy count for this setup. Stage bags by hole before mixing so an overdug first hole does not quietly consume the reserve for the rest of the run.
Hole sizing reality check
Each hole nets about 2.09 ft³ after post displacement before waste. If actual holes are wider, belled, or deeper than entered, rerun the table with the next diameter before buying.
Drainage and frost note
- Confirm frost depth, bearing soil, post embedment, and uplift/wind requirements locally.
- If gravel drainage, sleeves, forms, or post anchors are part of the detail, account for them before ordering concrete.
- Do not rely on concrete count as proof that a fence, deck, pergola, or sign post is structurally adequate.
Watch-outs
- Round or irregular holes are rarely perfect cylinders; auger wobble, rocks, bell-outs, and soil collapse can add concrete.
- Post size, post anchors, drainage gravel, sleeves, forms, frost depth, uplift, wind exposure, and soil conditions can change the detail.
- This is a materials estimate only, not structural, fence, deck, or footing design guidance.
Notes
Planning estimate only. Confirm hole depth, diameter, post embedment, frost depth, uplift/wind exposure, drainage gravel, soil conditions, local code, permits, and manufacturer guidance before digging or pouring.
Get a better answer from the Post Hole Concrete Material Estimator
- Start with the example values to see how the tool behaves.
- Swap in your own numbers, even if they are rough first-pass estimates.
- Change one input at a time so you can see what actually moves the result.
What the result means
The result is a planning estimate for how much material you may need. It helps you avoid underbuying, overbuying, or missing the parts around the main material.
How to use it
Run the project once with your best measurements, then run it again with extra waste or tougher site conditions. The difference is your ordering cushion.
What can change it
Supplier labels, product coverage, local code, jobsite surprises, delivery minimums, and installer judgment can beat the calculator. Use the result as a buying conversation starter.
Good for
Estimate bagged concrete for fence or deck post holes.
Check next
Compare your result with Fence Material Estimator, Deck Board Estimator, Concrete Calculator when you want more context.
Best habit
Run a conservative case and an optimistic case. The gap between them is often more useful than a single answer.
Common uses
- Estimate bagged concrete for fence or deck post holes.
- Account for post displacement, overdig, and waste buffer.
- Compare hole diameter assumptions before buying concrete mix.
Common questions
Is the Post Hole Concrete Material Estimator private?
Yes. CalcShelf calculators run without an account, do not save calculator entries, and do not put raw inputs into shareable URLs or analytics events.
How accurate is the Post Hole Concrete Material Estimator?
It is a material planning estimate. Product coverage, local code, site conditions, waste, delivery minimums, and installer judgment can change the final buy list.
What should I check after using the Post Hole Concrete Material Estimator?
Verify measurements, product labels, local code, substrate or site conditions, waste, accessories, delivery rules, and supplier guidance.
Which calculator should I try next?
Use the related calculators below to cross-check the same decision from another angle before you act.
Method behind the estimate
Construction estimators use common area, volume, coverage, package-rounding, and waste-cushion math based on user-entered project dimensions.
Why the detail matters
Supplier labels, code, site conditions, product specs, access, and contractor judgment can override the estimate. Treat the detail tables as buying context, not a final takeoff.
Privacy guardrail
Your calculator values are for you. CalcShelf does not require an account, save calculator entries, put your numbers into shareable URLs, or use raw inputs as analytics events.
Copy or print safely
Use any copy, print, or worksheet controls as local handoff tools for your own notes, supplier calls, lender questions, or implementation checklist. They are there to help you explain the result to a human.
Before acting
Treat the result as a decision draft, not a verdict. Recheck the source numbers, run a downside case, and verify the real-world rule, quote, label, or spec that controls the final answer.
Last reviewed: May 11, 2026. See methodology and editorial policy for formulas, assumptions, rounding, review approach, and limitations. Before buying or building, check product labels, local code, site conditions, and supplier or contractor guidance.