Count the spans in a straight fence run
A straight open run has one more post than the number of spans. Rails are counted per span, while pickets are estimated from their repeating width-plus-gap module. Gates and corners can change the layout and need separate treatment.
Measure and calculate
- Measure one straight uninterrupted run and choose its intended maximum post span.
- Enter rails per span when using rail mode.
- Use actual picket face width and clear gap for the picket count.
Posts = ceiling(run length ÷ intended span) + 1.
A worked example
- Inputs
- A 48 ft straight run is divided into 8 ft spans.
- Calculation
48 ÷ 8 = 6 spans; 6 + 1 = 7 posts.- Result
- 7 post
The initial estimate is 7 posts. With two rails per span, the same run uses 12 rails. This simple count does not place gates or determine safe post spacing.
Read the result
| Output or check | What it means for your project |
|---|---|
| Posts and rails | For one open run, posts equal whole spans plus one; rail count uses whole spans times rails per span. Shared corners and gates need a separate layout. |
| Pickets | Picket mode uses actual face width and clear gap. Check the end conditions rather than assuming every run finishes with the same gap. |
Common questions
Why is there an extra post?
Each open straight run needs a post at both ends; adjacent spans share their intermediate posts.
Can I add counts for several adjoining runs?
Check shared corners before adding them. Counting each run independently can count the same corner post twice.