How many posts, rails and pickets do I need for an 80 ft picket fence?
For the worked example (80 ft picket fence, 8 ft post spacing, 3 rails, 5½ in pickets with ½ in gaps) the material list is Posts: 11 posts (calculated 10 sections + 1, based on one straight run, no corners or gates); Rails: 30 rails (calculated 10 × 3, based on 3 per section × 10 sections); Pickets: 168 pickets (calculated 160 pickets before extra, based on 5.5 in pickets with 0.5 in gaps, 5% extra). Quantities to buy are whole units rounded up from the calculated amounts. Enter your own measurements in the calculator above for your exact list.
How to use this calculator
- Pick panel fence or picket fence.
- Enter the total length of one straight run.
- For panels, enter the installed section width (post spacing) from your fence system’s instructions. For pickets, enter the post spacing, rails per section and picket sizes from your product.
- Optionally enter concrete bags per post if you know what your installation needs.
- Copy, print or share the material list.
How this is calculated
- Sections = round up (fence length ÷ installed section width / post spacing)
- Posts = sections + 1
- Rails = sections × rails per section
- Picket module = picket width + gap
- Pickets = round up ((fence length ÷ module) × (1 + extra ÷ 100))
- Post concrete = round up (posts × bags per post), only if you enter it
Geometry is deterministic. Material coverage, density, installation waste and product yield can vary. We expose those assumptions so you can replace them with the values printed on the products you are actually buying. Treat every result as an estimate. Items on your list are labelled Calculated (straight from your measurements) or Estimated (depends on an assumption), and “Buy” quantities are whole units rounded up.
Sources
- Lowe’s – 4×8 spaced arched picket panel assembly and installation instructions (product document). For that product, post holes are marked 96 in post-center to post-center, and the document tells the installer to check local requirements. Basis for treating spacing as an input from your own product’s instructions rather than a fixed rule. This is one product’s document, not a general standard.
- Lowe’s – How to install a vinyl fence. General retailer guidance on setting posts for panel fences. Background only. Always follow the instructions that came with your panels.
Last reviewed: . See the methodology.
Assumptions
These starting values are used until you change them. They are typical, not universal. Check the label on the product you are buying.
| Assumption | Starting value | Where it comes from |
|---|---|---|
| Posts for one straight run | sections + 1 | Mathematical |
| Picket width | You enter it | You enter it (product / supplier) |
| Extra allowance | 0% | Common planning default |
Worked example
An 80 ft straight picket fence, posts 8 ft apart, 3 rails per section, 5½ in pickets with ½ in gaps, 5% extra:
- Posts: 11 posts · one straight run, no corners or gates
- Rails: 30 rails · 3 per section × 10 sections
- Pickets: 168 pickets · 5.5 in pickets with 0.5 in gaps, 5% extra
Common questions
Does this work for corners and gates?
Not directly. It counts one straight continuous run. Treat each straight run separately and add corner or gate posts and hardware yourself.
How far apart should posts be?
That is set by your fence system. Lowe’s installation documents give post-center-to-post-center spacing for a specific panel (96 in for one 8 ft picket panel), and other manufacturers add bracket and post allowances to the nominal panel width. Enter the installed spacing from your own instructions, which can differ slightly from the nominal panel width.
How much concrete per post?
We do not recommend one. Hole size and concrete depend on the fence, soil, wind and local requirements. If you know the number, enter it.
Guides
- How Many Fence Posts and Pickets Do I Need?Posts, rails and pickets from run length, spacing, picket width and gap.
- How Fence Post Spacing Changes Your Material CountPosts, rails and pickets at three post spacings for the same fence.
- How Many Deck Boards Do I Need?Rows from board width and gap, boards per row from stock length, rounded up.
- How Deck Board Width and Gap Change the Board CountWhy a wider board or gap can remove a row, shown on one deck.