How many fence posts do I need?
Measure the whole run, gates included, and count the gates. The fence between the gates is split into sections no longer than the post spacing. You need one post more than the sections, plus one for each gate. Lowe's suggests putting any short section at a corner or next to a gate, and none under 2 ft.
The spacing is usually set by your rails or panels: Lowe's gives 5 – 8 ft as typical. Local rules can ask for less. Hialeah, Florida's detail for a 6 ft wood fence needs posts 4 ft apart and at least 3 rails, so check with your building department.
Source Lowe's · Fence Installation Tips: Layout and Digging Post Holes (post spacing) ↗City of Hialeah, FL · Wood Fence Design Detail (Florida Building Code section 2328) ↗
How to calculate fence materials
Here it is with your numbers:
- Take off the gate: 100 − (1 × 4) = 96 ft of fence.
- Divide by the post spacing: 96 ÷ 8 = 12 sections.
- Posts: one more than the sections, plus one for each gate: 12 + 1 + 1 = 14 posts.
- Rails: 3 for each section: 12 × 3 = 36 rails.
- Pickets: the fence in inches divided by a picket: 1,152 ÷ 5.5 = 209.4545, rounded up to 210.
It means buying 14 posts, 36 rails and 210 pickets, plus what the gate needs.
Pickets sit side by side with an even gap, so a fence of pickets has one gap fewer than pickets. A picket sold as 6 in wide is 5-1/2 in once dried and planed, so use the width you measure. Gates are made to fit their opening and aren't counted here.
Source NIST · PS 20-25 American Softwood Lumber Standard, Table 3 (board sizes) ↗
Fence posts and pickets for common lengths
No gates, posts 8 ft apart, 3 rails per section, 5.5 in pickets with no gap.
FAQs
How do I calculate how many fence posts I need?
Divide the fence length by the post spacing and round up to get the sections, then add one post, plus one for each gate. A 100 ft fence with posts 8 ft apart is 12.5, so 13 sections and 14 posts.
Source Lowe's · Fence Installation Tips: Layout and Digging Post Holes (post spacing) ↗
Should fence posts be 6 or 8 feet apart?
Either can be right. Lowe's says spacing is set by your panels, rails or local building rules, and is typically 5 – 8 ft: 16 ft rails span 3 posts, so 8 ft apart. Windy areas can need closer posts: Hialeah, Florida's detail puts posts 4 ft apart for a 6 ft fence.
Can fence posts be 10 feet apart?
Lowe's puts typical spacing at 5 – 8 ft, set by the length of your rails or panels and by local building rules. Check both before spacing posts wider than that.
How many pickets do I need for 100 ft of fence?
With 5.5 in wide pickets side by side, 219 pickets (1,200 in ÷ 5.5 = 218.18, rounded up). For 200 ft it's 437. A gate's opening needs fewer, and gaps between pickets fewer still.
Source NIST · PS 20-25 American Softwood Lumber Standard, Table 3 (board sizes) ↗
How many pickets for a 6ft fence?
The height doesn't change the count; the width of the pickets does. An 8 ft section takes 18 pickets 5.5 in wide (96 ÷ 5.5 = 17.45). A "1 × 6" picket is 5-1/2 in wide once dried and planed.
Do you use 8 or 10 foot posts for a 6-foot fence?
Hialeah's fence detail uses 4 × 4 posts 8 ft long for fences up to 6 ft, with 3 rails. Lowe's says the hole should go below the frost line, typically 30 in deep (24 in for the post), so colder places may need longer posts.
Source City of Hialeah, FL · Wood Fence Design Detail (Florida Building Code section 2328) ↗
Sources
- Lowe's: Fence Installation Tips: Layout and Digging Post Holes (post spacing)
- City of Hialeah, FL: Wood Fence Design Detail (Florida Building Code section 2328)
- NIST: PS 20-25 American Softwood Lumber Standard, Table 3 (board sizes)