Fence Calculator
Pickets, posts and rails for a privacy or picket fence of any length.
Fence estimates fail at the corners and gates, not along the straight runs. The formula for a picket run is straightforward arithmetic; what catches people is that every corner needs a post, a gate needs two, and a gate opening removes pickets from the count but adds framing.
Post spacing is a structural decision, not a cosmetic one. Eight feet is standard for a six-foot privacy fence in normal soil. Go to six feet in sandy ground, on a slope, or anywhere the fence will catch serious wind — a post that fails takes the whole bay with it, and repairs mean digging out concrete.
How this calculator works
Every field is editable and the result updates as you type — nothing is submitted anywhere, all the maths runs in your browser. That matters for a number you are about to spend money on: you can see exactly which input moved the answer, and by how much.
What this calculation assumes
Assumes a straight run with pickets on centre and posts at regular spacing. Corners, gates, slopes and end returns all add material, and post depth to frost line is not counted — in cold climates, concrete and gravel for posts can rival the cost of the pickets.
Treat the result as an order-of-magnitude check rather than a final quantity. Product packaging changes, regional labour rates vary by a factor of two, and no calculator has seen your actual site.
Frequently asked questions
How many pickets do I need per foot of fence?
With 5.5 inch pickets and a quarter-inch gap, about 2.1 per foot. A 100 ft run therefore needs roughly 210 pickets. Narrower pickets or wider gaps change this quickly, which is why the calculator asks for both rather than using a fixed multiplier.
How far apart should fence posts be?
Eight feet is standard. Six feet for sandy soil, slopes, tall privacy fences, or exposed sites. Post depth matters just as much: one third of the post length should be in the ground, so an eight-foot post goes down about two and a half feet into concrete.
Do I need a permit for a fence?
Often, yes. Many jurisdictions cap fence height at six feet in a rear yard and four feet in front, and some require a setback from the property line. Check with your local building department before buying material — moving a fence after installation is far more expensive than the permit.
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