How the aluminum fence calculator works
Ornamental aluminum comes in welded sections that slot into punched posts, so the count starts from the maker's on-center spacing rather than a round panel width. The calculator fills each straight stretch between corner, end and gate posts with full sections, and the leftover becomes one section cut to fit.
Full sections = stretch length ÷ on-center spacing, rounded down. Cut section fills the leftover length − post width. Posts = sections + 1 on each stretch, with corners shared.
The on-center figures come from Jerith's installation instructions. Its residential line sets 6 ft sections at 72 1/2 in on center on 2 in square posts, or 73 in on 2 1/2 in posts. Fortress gives slightly tighter maximums for its Athens line: 71 3/4 in on 2 in posts and 72 1/4 in on 2 1/2 in posts. Use the figure printed on your own panel's sheet if it differs.
A worked example
The calculator opens on a 150 ft fence, 4 ft (48 in) high, with two corners and one 4 ft gate, on 2 in posts.
- The gate leaves 146 ft to fence: two 50 ft sides and two 23 ft stretches beside the gate.
- A 50 ft side is 600 in. Eight sections at 72 1/2 in use 580 in, leaving 20 in. Less the 2 in post, the last section is cut to fill 18 in.
- A 23 ft stretch is 276 in: 3 sections (217 1/2 in), then a cut section filling 56 1/2 in.
- That is 26 sections, 22 full and 4 cut, and 28 posts: 22 line, 2 corner, 2 end and 2 gate. Each post takes a cap.
- Concrete: 30 in holes, 6 in wide, over 6 in of gravel need about 0.9 bags of 50 lb fast-setting mix each, 26 bags in all.
With 2 1/2 in posts at 73 in, the counts stay the same here, and the cuts become 13 1/2 in and 54 1/2 in. If an 18 in stub at the end of a side looks odd, split the last two sections evenly instead. That takes a second cut but no extra material.
How deep do aluminum fence posts go?
Jerith's post depth chart ties depth to height: at least 18 in for 36, 48 and 60 in fences, 24 in for 42, 54 and 72 in, and 36 in for 84 and 96 in. The fence bottom sits about 2 to 3 in above the ground. Our default of 30 in follows Quikrete's rule of half the height above ground plus 6 in of gravel, which is deeper than the chart. At 24 in the same fence takes 19 bags. Where the ground freezes, go below the frost line either way; the fence post depth calculator works that out.
Which posts do I order?
Aluminum posts are punched for their job, so you order them by type. Jerith punches line posts on opposite sides, corner posts on two adjacent sides and end posts on one side. A gate post is an end post with walls twice as heavy. The material list gives the count of each, which is what the supplier needs.
Is a 4 ft aluminum fence tall enough for a pool?
For the CPSC's Safety Barrier Guidelines for Residential Pools, yes: the top of the barrier must be at least 48 in above grade. Some states and towns require 60 in, and the CPSC calls fences of 5 ft or more preferable. The pool check next to the material list tests the rest of the guidelines against your fence:
| Rule | Limit |
|---|---|
| Gap between pickets, rails 45 in or more apart | no 4 in sphere passes |
| Gap between pickets, rails under 45 in apart | 1 3/4 in, rails on the pool side |
| Gap under the fence | 4 in, or 2 in over grass or pebbles |
| Gates | open outward, self-closing, self-latching |
A latch release lower than 54 in has to sit on the pool side, at least 3 in below the top of the gate. Your local code has the final word, so check it before you order.
What does it cost?
The aluminum fence cost calculator prices the job from HomeAdvisor and Fixr ranges. If you are deciding between aluminum and steel or iron, the wrought iron fence calculator runs the same fence line with heavier 8 ft panels, and the fence calculator compares every fence type.