Article — Fence Picket Calculator
Fence picket calculator: count pickets, board feet, and waste
A fence picket calculator counts the pickets needed by dividing the fence length (in inches) by the pitch (picket width + gap). For 100 ft of fence with 3.5 in pickets and a 1.75 in gap, the pitch is 5.25 in and you need 229 pickets. Add 10 percent for waste and the order rises to 252.
The arithmetic is short, but the choices around it (picket width, gap, height, wood species) drive most of the cost and appearance of a wood fence. This guide walks through the formula, the standard lumber sizes, the spacing styles, and the lumber math behind a complete picket order.
What the fence picket calculator does
The tool above takes fence length, picket width, and gap, then returns the picket count, pickets per foot, total linear feet, and board feet. A preset menu fills the width field for common 1x4 (3.5 in), 1x6 (5.5 in), and 1x8 (7.25 in) lumber. The gate field subtracts any gate width from the picket count.
For an L-shaped or polygonal yard, run the calculator once per straight section and add the picket counts. The math is linear in length, so 60 ft + 40 ft gives the same total as a single 100 ft entry.
The fence picket pitch formula
Pitch is the repeating unit, defined as picket width plus gap. Picket count equals fence length (in inches) divided by pitch, rounded up. The conversion from feet to inches is where most hand-calculation errors creep in.
Pitch = Width + Gap (inches)Pickets = ceil(Length × 12 / Pitch)Per foot = 12 / PitchBoard ft = (0.75 × W × H × 12) / 144The pitch concept comes from machine design, where it means the distance between successive features. On a picket fence it has the same meaning: the distance from the centerline of one picket to the centerline of the next.
Standard fence picket widths
Lumber yards stock nominal 1x4, 1x6, and 1x8 pickets in 6 ft and 8 ft lengths. The actual dimensions are smaller than the nominal call-out because of the surfacing step: a nominal 1x4 is 0.75 in by 3.5 in actual.
The 1x4 picket is the traditional choice for a residential white picket fence. The 1x6 is the most common privacy-fence picket because it covers ground twice as fast and looks more substantial. The 1x8 is mostly used for board-on-board and shadowbox styles.
Fence picket spacing styles
Four spacing styles cover almost every residential fence: traditional, semi-private, privacy, and shadowbox. The calculator handles the first three directly; shadowbox doubles the count because pickets attach on alternating sides of the rails.
- Traditional picket gap equals picket width, even rhythm of wood and air
- Semi-private 0.5 to 1 in gap, blocks most sight lines
- Privacy 0 in gap, pickets butt edge-to-edge
- Shadowbox alternating sides on common rails, doubles count
- Board-on-board outer pickets overlap inner gaps by 1 in
- Spaced privacy 0.25 in gap accommodates seasonal swelling
Wood choice for fence pickets
The four species you see at most U.S. yards are pressure-treated southern yellow pine, western red cedar, redwood, and white cedar. Pressure-treated pine is the price leader at $2 to $4 per picket; cedar and redwood run $4 to $9 per picket. The USDA Forest Service Wood Handbook rates cedar and redwood as naturally durable, meaning they resist decay without chemical treatment.
The USDA Forest Service classifies wood durability by heartwood only. The pale outer sapwood on a cedar picket has no more decay resistance than untreated pine. That is why a high-quality cedar picket has a uniform reddish color top to bottom, and why a mostly-white picket is not really a cedar fence in the durability sense.
Service life varies with climate and ground contact. Pickets stop at the rail and never touch dirt, so they outlast the posts. Plan on 15 to 20 years for pressure-treated pine pickets, 20 to 30 years for cedar and redwood.
Board feet and lumber orders
Board feet is the lumber unit of trade: one board foot is 144 cubic inches of wood, or a piece 1 in thick by 12 in wide by 12 in long. The board-feet output from the calculator helps when ordering rough lumber, although most pickets are sold by the piece.
For a 6 ft tall 1x4 picket, board feet per picket equals (0.75 x 3.5 x 72) / 144, which is 1.31 board feet. A 100 ft fence with 229 pickets contains 300 board feet of lumber, plus another 30 percent or so for rails and posts.
Picket waste allowance
10 percent is the standard add-on for waste, cull, and future replacement stock. The calculator adds this automatically in the "with 10% waste" line. Bump to 15 percent for low-grade lumber or installations with many trim cuts (irregular yards, custom picket tops).
Pressure-treated pickets often arrive with a cracked or cupped percentage. Lay the bundle out and sort by quality before nailing; reserve the best pickets for the run nearest the house and use the rough ones at the back of the yard. Returning a few pickets is much easier than returning a finished section.
Picket installation tips
Set the rails before the pickets. A 6 ft fence uses two rails for 3 to 5 ft tall and three rails for 6 ft and up. Pickets attach to the rails with three nails per picket on a 6 ft fence: two at the top rail, one at the bottom (or two and one at the middle and bottom for three-rail layouts).
Build a spacer block the width of the chosen gap and use it instead of measuring each picket. A scrap of 1.75 in plywood between every picket gives perfect repeat spacing without a tape measure. The block also tests the fit before you commit a nail.
Leave a 2 to 6 in gap between the bottom of the pickets and grade. Pickets touching dirt rot first, no matter the wood species. A gravel mow strip under the fence line keeps the bottoms dry and lets a string trimmer pass without nicking the wood.