Fence Calculator
Estimate fence panels or posts from your fence run length and the actual panel width or post spacing you plan to use.
How to Use
- Choose Fence panels when you know the actual installed or coverage width of the fence panel product you plan to use.
- Enter the total straight-run fence length and the panel coverage width. Add an extra-panel percentage only if you want a purchasing margin.
- Choose Fence posts when you know the maximum center-to-center post spacing required by your product, plan, installer or local requirements.
- Enter the straight-run length and the maximum spacing. The calculator divides the run into equal intervals no longer than your entered spacing and adds one post at each end.
- Calculate corners, gates, terminal posts, special posts, footings and structural requirements separately from this quantity estimate.
Formula
- Panels before allowance
- base_panels = round up(fence_length ÷ panel_coverage_width)
- Panels with allowance
- panels_needed = round up((fence_length ÷ panel_coverage_width) × (1 + allowance ÷ 100))
- Post intervals
- intervals = round up(fence_length ÷ maximum_post_spacing)
- Posts for one run
- posts_needed = intervals + 1
Worked Example
A straight 50 ft fence run with a maximum post spacing of 8 ft.
- 50 ÷ 8 = 6.25, so round up to 7 intervals.
- Posts for one straight run = 7 intervals + 1 end post = 8 posts.
- Evenly distributing the run across 7 intervals gives about 7.14 ft between posts.
Result: 8 fence posts
About This Tool
What this tool does
This calculator provides two separate fence quantity estimates: whole panels from an entered panel coverage width, or posts for one straight run from an entered maximum post spacing.
When to use it
Use it for early material takeoffs when you already know the fence run length and either the panel product coverage width or the post spacing required for your chosen system.
What the result means
Panel quantities are rounded up to whole panels. Post calculations round the number of intervals up so the resulting even spacing does not exceed the maximum spacing you entered, then add one post at each end.
Assumptions & limitations
Each calculation treats the fence as one straight run. It does not automatically add corners, gates, terminal posts, bracing, rails, pickets, concrete, post depth, footing size, wind loads, structural design or code requirements. Use product instructions, drawings, installer guidance and local requirements for those decisions.