Fence Picket Calculator — Boards, Gaps & Layout
Plan individual fence pickets across unequal bays. See even gaps, inspect board positions, add whole spare boards and print your layout.
Plan the boards · see every gap
14 installed + 2 spare · 1 bay
A clear opening, actual board width and a layout that fits. Count each bay separately, then buy whole spare boards.
Edit your fence baysEqual gap 3.13333 in · end gaps 3.13333 in
Left edge 3.13333 in · centre 4.88333 in · right edge 6.63333 in
This board finishes 3.5 in wide.
Your picket layout
Measure the clear opening between the inside post faces. Add different bay widths separately. These examples replace every field and clear your quotes; each includes 10% spare boards.
Bay size 1
96 in clear opening · 1 bay
Your purchase list
- Bay size 1: 1 × 14 = 14 pickets · 96 in clear · gap 3.13333 in
Whole pickets of a suitable height, with the same face width. Gates are separate: leave their openings out. Posts, rails, fixings and structural design are not included. Solid mode trims the two outside boards equally; offcuts are not reused.
Add your supplier quotes
Use one currency and one tax basis throughout. Blank means unknown; enter 0 only for free or included items.
Incomplete subtotal — missing board price and delivery.
Mark list for the previewed bay
Measure each mark from the left inside post face. Values are rounded to five decimal places. Do not repeatedly step off a rounded spacing; check actual end and interior gaps before fixing.
| Picket | Left edge | Centre | Right edge | Finished width |
|---|
How many pickets do I need?
The answer depends on each clear bay, the actual board width and the treatment of both ends. For 96 in with 3.5 in boards and a preferred maximum gap of 3.5 in, equal end gaps need 14 boards. The remaining 47 in is shared among 15 spaces, giving 3.13333 in per gap. With 10% spare boards, buy 16.
Equal gaps or flush ends?
For N full-width boards of width W in a clear opening L, equal end gaps are (L − N × W) ÷ (N + 1). With boards flush at both ends, interior gaps are (L − N × W) ÷ (N − 1). Automatic mode chooses the smallest feasible whole count within your preferred maximum. Fixed mode uses your count and reports any excess gap.
What if I want no gaps?
Solid mode buys enough full boards to cover the bay, then shares the required width reduction between the two outside boards. A 96 in bay with 5.5 in stock uses 18 boards: 16 full-width boards plus two boards trimmed to 4 in each. Buy 20 with 10% spares. A very narrow single-board bay trims that one board to fit. This is a geometric layout, not a prediction of gaps after the timber dries.
Why separate unequal bays?
Rounding and end gaps happen within each opening. Two 96 in bays plus one 72 in bay use 14 + 14 + 10 = 38 boards for the spaced example, then 4 spares. Summing all lengths before rounding can produce the wrong purchase quantity.
Measurement and scope
One vertical plane of parallel pickets only, up to 24 bay sizes and 500 boards per bay. Enter the horizontal clear width, not post-centre spacing, outside-to-outside width or a sloping rail length. Shadowbox, overlapping boards, gate cladding and stepped or raked geometry need different layouts. This tool does not approve pool barriers, guardrails or structural suitability.
Lowe’s picket installation guide describes using a spacer for equal picket gaps and checking the work as boards are installed. The formulas above are this planner’s explicit geometric model. Follow your product instructions for fixing and timber movement.
Continue your project
Buying complete panels? Use the panel fence calculator for panels, shared posts and gate openings. For lumber quoted by volume, use the board-foot purchase calculator.
