Fence Calculator
Enter the fence length, post spacing and gates and get the posts, rails, pickets and concrete bags to buy.
Maximum, centre to centre.
A nominal 1×6 is 5.5 in actual.
A 4×4 is 3.5 in.
Post spacing, hole size and depth are set by your fence design, local code and frost depth; the page uses whatever you enter.
146 ft of fence plus 1 gate
21 posts · 38 rails · 292 pickets
19 sections · 52 bags of 50 lb concrete (0.92 cu ft per post)
| Sections | 19 (no wider than 8 ft) |
| Posts | 21 (sections + 1, plus 1 per gate) |
| Rails | 38 (2 per section, each about one section long) |
| Pickets | 292 |
| Concrete | 52 × 50 lb bags |
What this page cannot tell you
Corners and ends sometimes take heavier posts, and a run broken by gates may need an extra post where sections do not divide evenly. Gate hardware, the gate panels themselves, fasteners and gravel at the base of the hole are not counted. Call 811 before digging in the US.
How to calculate fence materials
- Enter the fence length and spacing. Total length and the maximum post spacing.
- Add gates. How many and how wide.
- Describe the panels. Rails per section and picket width and gap.
- Size the post holes. Diameter, depth, post size and bag size for concrete.
10 fence projects this sizes
Privacy fence
A homeowner orders posts and pickets for a 150 ft backyard fence.
Picket fence
Someone works out picket count with a 2 in gap.
Split-rail fence
Pickets set to 0 gives posts and rails only.
Garden fence
A gardener fences a vegetable plot with one gate.
Dog run
A pet owner prices a small run.
Farm fencing posts
A landowner counts posts for a long run.
Replacing rotten posts
Someone works out concrete bags per post.
Comparing post spacing
6 ft versus 8 ft spacing is compared on post count.
Contractor quotes
A homeowner checks a materials list.
Pool fence planning
Someone sizes posts before checking their local pool code.
How the fence materials are worked out
Sections = (length − gate widths) ÷ spacing, rounded up; posts = sections + 1 + one extra per gate; rails = sections × rails per section; pickets = fence length in inches ÷ (picket width + gap), rounded up.
Concrete per post = hole volume (π × r² × depth) minus the post's volume in the hole. Bags use the QUIKRETE Concrete Mix No. 1101 yields (50 lb ≈ 0.375 cu ft, 80 lb ≈ 0.60 cu ft).
Limits: spacing, hole size and depth come from your fence design and local code, including frost depth. Corners, ends and gate posts often need heavier posts. Gate hardware and fasteners are not counted. Call 811 before you dig in the US.
Frequently asked questions
How many fence posts do I need?
Fence length ÷ post spacing, rounded up, plus one, plus one per gate.
How far apart should fence posts be?
That depends on the fence design and materials; enter your spacing.
How many pickets per foot?
12 ÷ (picket width + gap). 5.5 in pickets with 0.5 in gaps need 2 per foot.
How much concrete per fence post?
A 10 in hole 24 in deep around a 4×4 needs about 1.1 cu ft — three 50 lb bags.
Does it count gate posts?
Yes, one extra post per gate.
What is a 4×4's actual size?
3.5 × 3.5 in.
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