Fence Post Concrete Calculator
Setting fence posts, mailbox posts, or deck footings? Enter the hole diameter and depth below — this is the same round-column math builders use for post holes, giving you cubic yards, cubic feet, and bag counts for a single hole or a whole fence line. Use "Add to job list" to total up every post on the run at once.
Dimensions
Order options
Add to job list
Pouring more than one column? Give this one a label and add it — the results panel keeps a running grand total.
FAQ
- Is a fence post footing the same as a column?
- Yes — for a round post hole, pick Round and enter the hole diameter and depth as height. Sonotube forms are usually sold by diameter, matching this calculator directly.
- Should I subtract the post itself from the volume?
- This calculator gives the full hole volume. If a large post or pier will displace a meaningful amount of concrete, subtract its own volume from the result.
Exact volume
- 0.00
- yd³
- 0.0
- ft³
- 0.00
- m³
Estimated weight0 lb / 0 kg
Recommended order (incl. waste)
- 0.00
- yd³
- 0.0
- ft³
- 0.00
- m³
Bags needed
Estimated cost$0
Job grand total
- 0.00
- yd³
- 0.0
- ft³
- 0.00
- m³
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Fence post FAQ
- How wide should a fence post hole be?
- A common rule of thumb is 3 times the post's width — for a 4×4 post that's roughly a 10–12 inch diameter hole. Wider holes need more concrete but hold posts more securely.
- How deep should a fence post hole be?
- Typically a third of the post's above-ground height, and always below your local frost line — often 24–36 inches for residential fencing, but check local code. Enter that depth as "Height" above.
- Do I subtract the post itself from the volume?
- For typical 4×4 or 6×6 wood posts the difference is small enough to fold into your waste allowance. For large posts or piers, reduce the diameter slightly to account for the post's footprint.