How it’s calculated
- Fenced length = total − gates × gate width
- Sections = fenced length ÷ post spacing, rounded up
- Posts = sections + 1 + gates + corners
- Pickets = fenced length ÷ (picket width + gap) × (1 + waste %)
- Concrete per post = hole volume − post volume
Worked example
100 ft privacy fence with one 4 ft gate, posts 8 ft apart, 5.5 in pickets with no gap, 2 rails, no waste.
Inputs
- Total fence length
- 100 ft
- Number of gates
- 1
- Gate width (each)
- 4 ft
- Corners and ends between runs
- 0
- Post spacing
- 8 ft
- Rails per section
- 2
- Picket width
- 5.5 in
- Gap between pickets
- 0 in
- Extra pickets for waste
- 0 %
- Post hole diameter
- 10 in
- Post hole depth
- 30 in
- Post width (actual)
- 3.5 in
- Concrete bag size
- 80 lb
Results
- Posts
- 14
- Pickets / boards
- 210
- Rails
- 24
- Sections
- 12
- Bags of concrete
- 27 bags
Assumptions and limits
- Each gate opening adds one post (a gate splits the run).
- Gate leaves themselves are not included in picket count.
- Square posts set full depth in concrete.
Verify the result against the applicable local code, adopted code edition, manufacturer instructions and project requirements. See our methodology.
Questions
How many fence posts do I need for 100 feet?
At 8 ft spacing with one 4 ft gate, 96 ft of fence needs 12 sections and 14 posts (13 for the run plus 1 for the gate).
How many pickets per 8 ft section?
With 5.5 in pickets and no gap, an 8 ft section (96 in) needs about 17.5, so 18 pickets.