Post Hole Concrete
Cylindrical volume; ~0.6 ft³ per 80 lb bag rule-of-thumb.
Inputs
Results
Volume
16.49 ft³
≈ 5 wheelbarrows
80 lb bags28
How to Use This Calculator
- Enter the hole diameter in inches — a common post hole is 10–12 inches wide.
- Enter the hole depth in inches — fence posts typically go 1/3 of their above-ground length into the ground.
- Enter the number of post holes.
- Read the total concrete volume in cubic feet and the number of 80 lb bags needed.
How the result changes with Hole Ø (in)
| Hole Ø (in) | Volume |
|---|---|
| 5.7 | 3.72 ft³ |
| 17 | 33.1 ft³ |
| 32 | 117.29 ft³ |
| 43 | 211.78 ft³ |
What each input means
- Hole Ø (in)
- Diameter of each post hole in inches. Common sizes are 10-12 inches for fence posts, 14-18 for deck posts.
- Depth (in)
- Depth of each hole in inches. A common rule: set posts at least 1/3 of their above-ground height below grade, and below frost line.
- Holes
- Total number of post holes to fill with concrete.
How this is calculated
Worked example, using the default values
- Identify Input ParametersHole Ø (in) = 12, Depth (in) = 42, Holes = 6 = 3 input(s) provided
- Calculate VolumeVolume16.49 = 16.49
Engine last updated . Checked against 1 independently-derived test — how we verify calculators.
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