Fence Calculator — Posts, Rails, Pickets & Concrete
Posts, rails, pickets, panels, chain link or wire, gates and concrete for any fence.
Units and currency
Fence runs and gates
Fence and posts
Post holes and concrete
Shopping list
| Item | Quantity | Price | Cost |
|---|---|---|---|
| Total of the prices entered | — | ||
Post layout
| Run | Segment | Bays | Posts apart |
|---|
About the Fence Calculator — Posts, Rails, Pickets & Concrete
Plan a fence from its sides: enter each straight run, put gates where they go, and say whether the runs join at corners or close a loop. The calculator spaces the posts evenly — never further apart than you allow — and counts line, end, corner and gate posts, then works out the materials for the style you build: rails, pickets and nails for a wood fence; ready-made panels; chain-link fabric with its rails, tension wire and every fitting; barbed wire; or welded and woven mesh.
Post holes follow published rules — QUIKRETE's for wood posts and the Chain Link Fence Manufacturers Institute's for chain link — or your own size, and the concrete comes out in bags or cubic metres. Every line of the shopping list takes a price.
How to use it
- Choose Metric or US units. Add each run — one straight side, measured between the centres of its end posts — and gates in it, with their distance from the start of the run (leave it empty to centre them). Say whether the runs join end to end, close a loop or are separate.
- Pick the style and enter the height above ground and the largest post spacing you want (for panels, the panel width sets it).
- Fill in the style's own sizes: pickets and rails, panels and brackets, chain-link rolls and rails, strands of barbed wire, or mesh rolls and staples.
- Check the post holes: the rule for your fence fills them in, or enter your own. Choose the concrete — bags with their yield, or site-mixed by volume — then type prices into the shopping list and copy or download it.
Examples
22 posts (16 line, 2 end, 2 corner, 2 gate) in 20 bays; 276 pickets 3.5 in wide with 2.5 in gaps; 40 rails of 8 ft. Holes 10.5 in × 30 in with 6 in of gravel: about 0.86 ft³ of concrete each — 51 bags of 50 lb fast-setting mix in all.
10 panels (one cut to 0.53 m) and 11 posts
17 posts (14 line, 1 end, 2 gate); 3 rolls of 50 ft fabric; 7 top rails of 21 ft with 6 sleeves; 2 tension bars, 8 tension bands, 4 brace bands, 154 ties, 98 hog rings. CLFMI footings 7.6 in across × 24 in deep for the line posts.
200 posts (196 line, 4 corner); 3,200 m of wire = 13 rolls of 250 m; 800 staples
How the posts are counted
Gates split a run into segments. Each segment ends at a terminal post — an end, corner or gate post — and is divided into equal bays no longer than your post spacing: bays = segment length ÷ spacing, rounded up, and line posts = bays − 1. Runs that join share their corner posts; a closed loop has no end posts. Two gates side by side share the post between them. For panel fences the posts are one panel width plus one post width apart, and the last panel of a segment is cut to fit.
Post holes and concrete
For wood and steel posts the calculator starts from the QUIKRETE "Setting Posts" guide: a hole about 3 × the post width across and 1/3 of the post's length deep plus 6 in (150 mm) of gravel, with concrete up to 3–4 in below the top and soil above it. With 1/3 of the post in the ground, a post stands 2/3 of its length above it, so the posts are 1.5 × the fence height long. Posts that carry a structure, such as a deck, go at least 6 in below the frost line.
Concrete per hole = π/4 × hole diameter² × concrete depth − the post's cross-section × that depth. Bag yields come from the manufacturer's data sheets — QUIKRETE Fast-Setting Concrete Mix: 50 lb ≈ 0.375 ft³, 60 lb ≈ 0.45 ft³, and the metric bags sold in Canada 25 kg ≈ 11.6 L and 30 kg ≈ 14 L; QUIKRETE Concrete Mix: 40 lb ≈ 0.30 ft³, 60 lb ≈ 0.45 ft³, 80 lb ≈ 0.60 ft³. For any other bag, enter the yield printed on it.
Chain link (CLFMI guide specification)
The Chain Link Fence Manufacturers Institute's product manual sets: line posts no more than 10 ft apart; footings at least 24 in deep plus 3 in for each foot of height over 4 ft, and 4 × the post diameter across (3 × above 4 in); fabric fixed at terminal posts with a tension bar and tension bands no more than 12 in apart; ties every 12 in on line posts and 18 in on the top rail; hog rings every 18 in on the tension wire, 4 in up from the bottom; top rail in 21 ft lengths joined with sleeves, ending in a rail end and brace band; terminal posts braced and trussed at 6 ft and higher (5 ft without a top rail). Line post sizes come from its Table 7, terminal posts are one size larger, and swing-gate posts follow the ASTM F900 table it quotes.
Limitations
- Runs are straight; for a curve, add it as several short runs.
- Rails are counted so that joints fall on posts; pickets and boards are counted for the full length, including over the posts.
- Hole sizes are the published rules of thumb — frost depth, soil, wind and local codes can need deeper or wider footings. Gate posts on wide or heavy gates need the gate maker's advice.
- Barbed and welded wire counts are geometry: the wire, rolls and fixings for the strands and spacing you choose, not a livestock fencing design.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How many fence posts do I need?
For each straight run, divide its length by the post spacing, round up and add one; then add a post on each side of every gate and take one off for each corner that two runs share. The calculator does this for every run and segment and lists line, end, corner and gate posts.
How much concrete per fence post?
For a 4×4 post (3.5 in) in a 10.5 in hole with 20 in of concrete, (π/4 × 10.5² − 3.5²) × 20 = 1,487 in³ ≈ 0.86 ft³ — about 2.3 bags of 50 lb fast-setting mix. QUIKRETE's data sheet gives two 50 lb bags for a 3 in post in a 9 in hole 30 in deep.
How deep should fence posts be?
QUIKRETE's rule is a third of the post's length in the ground plus 6 in of gravel — 2 ft for a 4 ft fence, 3 ft for a 6 ft fence. CLFMI asks chain-link footings to be at least 24 in deep plus 3 in for each foot of height over 4 ft. Go below the frost line where the ground freezes.
How far apart should fence posts be?
For a rail fence, no further apart than your rails are long, so that every rail ends on a post; chain-link line posts are at most 10 ft (3.05 m) apart (CLFMI). Enter the largest spacing you will accept — the calculator spaces the posts evenly at or below it.
Can I count the gates?
Yes. Add each gate to its run with its width and, if it is not centred, its distance from the start of the run. Gate posts are counted, the opening is left out of the fabric, rails and pickets, and the gates appear in the shopping list by width.