Aluminum fence calculator
Panels = run length ÷ the maker’s post spacing on center: a 50 ft run at 71.75 in centers takes 8 full panels and 1 shortened panel, with 10 posts.
Example: replace these measurements
Your material list
9 aluminum fence panels+ 1 more item on the list
9 aluminum fence panels
50 ft measured run
Your shopping list
- 9 aluminum fence panels
- 10 total posts
Quantities and package details
- Post centers
- 71.75 in
- Full panels
- 8
- Shortened panels
- 1
- Shortened bay 1 (Fence section)
- posts 26 in apart on center; cut an equal amount from each end of the panel
- Total posts
- 10
- End posts
- 2
- Corner posts
- 0
- Gate or stair posts
- 0
- Grade-change posts
- 0
- Line posts
- 8
- Gates
- 0
- Fence length along the slope
- 50 ft
- Same runs as a wood picket fence
- 124 pickets with 10% extra, 21 rails and 8 posts, with bays up to 8 ft
Panels are set post center to post center. Gate kits, brackets and caps come from the system’s parts list.
The calculation
- Post centers: 71.75 in
- Fence section, 0 to 50 ft: 600 in ÷ 71.75 = 8.36 → 8 full panels and 1 shortened
Common questions
How far apart are aluminum fence posts?
Use your fence maker’s figure. Fortress gives 71 3/4 inches on center at most for its Athens fence with 2-inch posts.
Source: Fortress Building Products: Athens aluminum fence installation instructions. Listed on the Sources page.
How do I fit a short bay?
Cut the panel to fit, taking an equal amount off each end, as Fortress instructs. Or choose equal bays so that every panel is shortened a little.
Source: Fortress Building Products: Athens aluminum fence installation instructions. Listed on the Sources page.
How far apart are the gate posts?
Fortress leaves a clear gap between the two gate posts 1 1/4 to 2 1/4 inches wider than the gate panel. The gate box here takes the distance between post centers, so add one post width to that gap: a 48-inch gate with 2-inch posts and a 49 1/4-inch gap is 51 1/4 inches on center.
Source: Fortress Building Products: Athens aluminum fence installation instructions. Listed on the Sources page.
How to plan the quantity
Enter each straight section between fixed posts, measured flat. Place a gate by its first post’s distance from the start and the distance between the two gate posts. Start a new section at each corner or change of grade, and choose how it joins the previous one so shared posts are counted once.
Each stretch between fixed posts gets as many full panels as the maximum post spacing allows; the leftover bay takes a shortened panel. Fortress says to cut an equal amount from each end of a shortened panel, and the list gives the post center distance for that bay.
Fortress also leaves a clear gap between the gate posts slightly wider than the gate panel; its figure, and how to turn it into post centers, is under Common questions. Enter the gate post spacing on center.
The list ends with the same runs as a wood picket fence, so you can weigh panels against pickets on your own layout.
Before you order
- Steel and aluminum systems differ in post spacing, brackets and racking on slopes. Use the maker’s own figures for the system you buy.
- Gate hardware, post caps, mounting brackets and footing sizes come from the system’s instructions and the site.
Before ordering, read the guide: How much tile do I need? Layout, cuts and boxes. Or choose another calculator.