How the fence calculator works
Enter one measured infill run with gate openings already removed. Choose wood, vinyl, or chain link so the material formula matches the product—not a generic “panel” swap. The tool counts posts for that layout, proposes a planning post depth (overridable), sizes a conservative hole for the counted posts, and converts annular concrete volume into whole Quikrete bag counts. The working panel shows every intermediate step.
For the full planning cluster—not just this tool—see the fence calculators and material guides hub. Sourcing rules live on the methodology page.
How many fence posts do I need?
On a straight wood or vinyl segment, sections are ceil(run ÷ spacing), and posts are sections + 1, plus any extra terminals you enter for gates, corners, or separate runs. That is the familiar ceil(length ÷ spacing) + 1 pattern—but only inside one uninterrupted segment. Do not stretch one continuous-run formula across corners or gates.
Chain link splits the count: CLFMI’s product manual caps line-post spacing at 10 ft on center; terminals sit at ends (and at extras you add). See how many fence posts for worked 50–200 ft examples.
Fence post depth considerations
The depth field is labeled a planning estimate. Quikrete’s Setting Posts in Concrete guide states dig ⅓ to ½ of the above-ground post length, plus 6 inches of gravel. This tool uses the deeper (½) endpoint, then takes the maximum of that baseline, any local depth you enter, and—for chain link—CLFMI’s footing minimum (24 in + 3 in per foot of height above 4 ft). Frost depth, soil, wind, gates, and product sheets can all override a rule of thumb. This is not structural engineering or permit approval.
For a transparent comparison of Quikrete ⅓ / ½, CLFMI, and local depth with gravel called out separately, use the dedicated fence post depth calculator. Jump to this page’s post-depth inputs for the full-run takeoff, or read the explanatory fence post depth guide.
How to calculate fence pickets
Convert the run to inches, then ceil(run inches ÷ (picket width + gap)), then apply the editable wood waste percent (default 10% — trade convention, not a code table). The starting picket width (5.5 in) is NIST PS 20-25’s minimum dressed-dry face for nominal 6-inch softwood—not a promise about every dog-ear SKU. There is no universal picket gap; privacy layouts often run tight, spaced layouts leave a deliberate reveal. For end-bay remainder and even spacing across posts, use the dedicated fence picket calculator. Guide with examples: fence picket spacing.
Concrete bags per fence post
Concrete volume is an annular cylinder around the post: hole volume minus post displacement, times the post count. Units are converted to feet before multiplying. Bags use Quikrete Concrete Mix No. 1101 yields (0.30 / 0.45 / 0.60 ft³ for 40 / 60 / 80 lb)—not one generic yield for every bag size. Excavation depth shown includes gravel; concrete volume does not. Jump to concrete inputs or concrete bags per post.
Wood, vinyl, and chain-link material differences
Wood repeats by board face + gap. Vinyl repeats by manufacturer center-to-center section width (the 8 ft default is a Barrette BOM example—replace it). Chain link orders mesh in linear feet of fabric for the run (gates already excluded); mesh length is not a complete fittings list. Comparison table: wood, vinyl, and chain-link takeoffs.
Gates, corners, end posts, and terminal posts
Break the job at every end, corner, and gate before you type a length. This v1 tool models one infill run plus an “extra gate / corner posts” count—it does not auto-detect corners from a perimeter. Chain-link terminals are counted separately from line posts. Workflow: gates and terminal posts.
Worked fence-material example
Straight wood run, defaults in the tool: 100 ft excluding gates, 8 ft post spacing, 5.5 in pickets, 0 in gap, 10% wood waste, 6 ft above-ground height, 4 in square post, 10 in planned hole (raised to 12 in by the 3× Quikrete baseline), 10% concrete overage.
sections = ceil(100 ÷ 8) = 13
posts = 13 + 1 = 14
pickets before waste = ceil(1200 ÷ 5.5) = 219
pickets with 10% = 240
planning embedment = 6 ft × 12 × 0.5 = 36 in
excavation = 36 + 6 gravel = 42 in
concrete (all posts, with overage) ≈ 31.15 ft³ → 52 × 80 lb bags
Reproduce it in the calculator above; change any input and the working updates.
Assumptions and limitations
- Rails, fasteners, caps, tension bands, brace hardware, gates as framed assemblies, and SKU-specific roll/bundle sizes are not calculated—reliable rail counts need fence-type-specific manufacturer layouts we will not invent as “two rails per bay.”
- One hole size is applied to every counted post; oversized gate/corner footings are separate.
- No prices, labor, or permit approval.
- Post depth is a planning estimate, not a frost map or engineering stamp.
Related fence guides
- How Deep Should a Fence Post Be? Quikrete, Frost & Gravel — Why post depth is local, how Quikrete and CLFMI baselines differ, and how to override the planner.
- How Many Fence Posts Do I Need? — Worked counts for 50–200 ft runs at planning spacings, plus why corners and gates break the formula.
- Fence Picket Spacing and Count — Width plus gap, unit conversion, privacy vs spaced layouts, and rounding — without a universal gap rule.
- How Many Bags of Concrete per Fence Post? — Annular hole volume, Quikrete bag yields, and why one post’s bags do not scale from fence length alone.
- Fence Material Takeoff: Wood vs. Vinyl vs. Chain-Link — What each fence type counts in units, what the calculator estimates, and what you still order separately.
- Planning Fence Gates, Corners, End Posts, and Terminal Posts — Break the layout into segments before you enter a length — corners, gates, and chain-link terminals.
- Fence calculators and material guides (hub)
- How Many Bags of Concrete Do You Actually Need — post-hole depth conflict with Quikrete docs