Hypothetical planning example
Four-post concrete bag yield
Hole volume, project-level bag rounding, and why bag yield is an editable assumption — not a brand promise.
Updated 2026-07-21 · Methodology
Question this answers
How many concrete bags does the calculator buy for a short run of freestanding posts?
Assumptions
- Short post run sized to the FP-RS-05 fixture
- Default hole diameter/depth and bag-yield settings from the project
- Structure posts (if any) are excluded from concrete
- Bags are rounded at the project level after summing hole volume
Hypothetical planning example. These inputs and results explain and test Fence Planner. They do not describe a customer project or completed installation.
Plan view
Deterministic diagram from the same fixture the planner loads — not a photo of a finished job.
Calculator result
Derived with the shared materials engine — not hard-coded in this page.
- Total fence length: 25 ft
- Fill length (excludes gate openings): 25 ft
- Posts: 4 total (end 2, line 2, corner 0, gate 0, terminal 0, structure 0)
- Concrete bags (project rounding): 25
- 3 full panels, 3 panels to buy (no cut bays)
| Item | Qty | Unit |
|---|---|---|
| 4x4 fence posts4x4 x 10 ft ground-contact | 4 | ea |
| Wood fence panels6 ft H × 8 ft W wood fence panel | 3 | ea |
| Concrete bags12 in × 36 in holes | 25 | bags |
| Pyramid post capsSized for 4x4 posts | 4 | ea |
| Panel mounting bracketsRail/panel brackets (system-matched) | 12 | ea |
| Bracket mounting screws2-1/2 to 3 in exterior screws · HDG or stainless | 50 | ea |
What this result means
- Bag yield is an assumption you can edit — verify against the bag label you will buy.
- Hole size drives volume more than “rules of thumb” on social media.
- Use the dedicated concrete calculator when you only need bags, not a full layout.
What this scenario shows
- Concrete tied to freestanding posts, not every drawn point
- Project-level rounding of bag count
- How changing yield or hole size would change the shopping number
What this does not prove
- Does not look up frost-line depth by ZIP code.
- Does not certify structural post embedment for wind or soil type.
- Not a retailer quote for a named concrete brand.
Open this exact example in the planner
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Open in plannerCalculations follow published methodology. Corrections welcome via contact.