Material calculator
Fence calculator — posts, panels & concrete
Estimate fence posts, equal sections, panel or picket counts, and concrete from the run length and post-hole dimensions. Concrete uses annular volume: hole volume minus buried post volume.
You'll need
20 posts
Fence posts
- Fence sections
- 19 sections
- Panels
- 19 panels
- Pickets
- 328 pickets
- 80 lb concrete
- 39 bags
- Concrete volume
- 23.0 cubic feet
What this assumes
- Posts = ceil(150 ft ÷ 8 ft) + 1 = 20.
- Concrete per post subtracts a 3.5 in square post from a 10 in diameter × 30 in deep hole.
- 80 lb concrete bag count uses the cited 0.60 ft³ per bag yield.
Coverage rates & sources
Every number this calculator uses is a published engineering constant — not an estimate we made up. Here is exactly what it assumes and where each value comes from.
- Typical post spacing: 6–8 ft (default 8)Source: Standard residential fence post spacing (Omni/fence-industry guidance)
- Post count formula: length/spacing + 1Source: Geometry (n sections need n+1 posts)
- 4×4 actual dimension: 3.5 inSource: Nominal-to-actual lumber (4×4 = 3.5"×3.5")
- 6×6 actual dimension: 5.5 inSource: Nominal-to-actual lumber (6×6 = 5.5"×5.5")
- Hole diameter for 4×4: 10–12 inSource: Standard (≈3× post width) — fence-install guidance
- Hole diameter for 6×6: ~18 inSource: Standard for 6×6 posts
- Min burial depth: 24 in (6 ft fence) / 30–36 in (8 ft)Source: ≥1/3 of post length, min 24"; below frost line where applicable (fence-install guidance)
- Annular concrete volume: hole volume minus buried post volumeSource: Geometry — cylinder volume for the hole minus square-post prism volume
- 80 lb concrete yield: 0.60 ft³/bagSource: Quikrete/Sakrete (shared table)
Before you buy
- Post count assumes equal sections and a straight run; corners, gates, end posts, and grade changes may need extra posts.
- Set posts below the frost line in cold climates and at least one-third of the post length; local code governs depth.
- Gate posts and corner posts often need a bigger hole and more concrete; fast-setting post-set concrete may use a different bag yield.
This is a planning estimate, not a substitute for a pro's on-site measurement. For load-bearing, structural, or code-regulated work, confirm quantities with a licensed contractor.
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