What Is a Privacy Fence Calculator?
This Privacy Fence Calculator estimates the core materials for a wood privacy fence: the number of pickets (vertical boards), posts, and rails (horizontal stringers). Instead of guessing at the lumber yard, you can plan your project and budget with confidence using just a few measurements.
How to Use It
Enter the total fence length in feet, the picket width in inches (a common dog-ear picket is 5.5 in), the post spacing in feet (typically 6–8 ft), and the number of rails per section (usually 2 for fences up to 6 ft, or 3 for taller fences). The calculator returns pickets, sections, posts, and rails instantly.
The Formula Explained
Pickets are found by converting the fence length to inches and dividing by the picket width, then rounding up: \( \text{pickets} = \lceil \text{length} \times 12 / \text{picket width} \rceil \). This assumes side-by-side (board-on-board not included) installation. The fence is divided into sections by post spacing: \( \text{sections} = \lceil \text{length} / \text{post spacing} \rceil \). You need one more post than there are sections, so \( \text{posts} = \text{sections} + 1 \). Rails equal \( \text{sections} \times \text{rails per section} \).
$$\begin{gathered} \text{Pickets} = \left\lceil \frac{12 \times \text{Length (ft)}}{\text{Picket Width (in)}} \right\rceil \\[1.5em] \text{Sections} = \left\lceil \frac{\text{Length (ft)}}{\text{Post Spacing (ft)}} \right\rceil \\[1em] \text{Posts} = \text{Sections} + 1 \\[1em] \text{Rails} = \text{Sections} \times \text{Rails / Section} \end{gathered}$$
Worked Example
For a 100 ft fence with 5.5 in pickets, 8 ft post spacing, and 2 rails per section: pickets = \( \lceil 1200 / 5.5 \rceil = \lceil 218.18 \rceil = \) 219. Sections = \( \lceil 100 / 8 \rceil = \lceil 12.5 \rceil = \) 13. Posts = \( 13 + 1 = \) 14. Rails = \( 13 \times 2 = \) 26.
FAQ
Does this include gaps between pickets? No — this estimate assumes pickets are installed flush (touching). For spaced or shadow-box styles, add extra width per picket accordingly.
Should I buy extra material? Yes. Add 5–10% for cuts, waste, and warped boards.
What about gates and concrete? Gates replace a section of pickets and need hardware; posts are typically set in concrete (about 1–2 bags per post). These are not included here.
