Board-on-Board Fence Calculator
Use this board-on-board fence calculator to estimate the number of posts, sections, rails, pickets, and the post length required for a privacy fence layout.
Fence Material Estimate
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Quick Answer: Omni's formulas estimate posts and sections from fence length and post spacing, while pickets are estimated from fence length, picket width, and overlap.
How to Calculate
- Enter fence length: Use the total fence run you want to build.
- Set the post spacing: Typical post spacing falls between 6 and 8 feet, or about 2 to 3 meters.
- Set the picket layout: Provide the fence height, picket width, overlap, and rails per section.
- Review counts: The calculator returns posts, sections, rails, pickets, and a recommended post length estimate.
Formula
posts = ceil(fence length / post space + 1)
| Variable | Meaning | Unit |
|---|---|---|
| fence length | Total planned fence run | length |
| post space | Spacing between fence posts | length |
| picket width | Width of one picket | length |
| picket overlap | Overlap between adjacent pickets | length |
Worked Examples
Privacy fence - Typical backyard fence
- Fence length: 60 ft
- Post spacing: 8 ft
- Fence height: 6 ft
Result: Roughly 9 posts, 8 sections, and post length of 9 ft
The 1.5x rule for post length helps account for burying roughly one-third of the post.
Interpretation Table
| Range | Meaning | Action |
|---|---|---|
| More sections | Longer fence or tighter post spacing | Expect more rails, more posts, and more labor. |
| More pickets | Wider fence or less overlap efficiency | Double-check your overlap and gate openings before ordering. |
| Longer posts | Taller fence | Confirm embedment depth, frost-line requirements, and local code. |
Frequently Asked Questions
A board-on-board fence uses overlapping pickets to improve privacy and reduce direct sightlines through the fence.
That rule of thumb allows roughly one-third of the post to be buried for support.
No. Add gate materials separately because hinges, frames, and openings change the picket and rail layout.
Note: This calculator gives estimating values only. Soil conditions, footing depth, local code, and gate framing can all change the final material takeoff.
References
Last reviewed: March 14, 2026