Fence Calculator
Estimate the posts, pickets and rails for a wood privacy fence. Assumes 8 ft post spacing, 5.5 inch pickets butted tight, and 2 rails per section.
Fence calculator
How it's calculated: Posts = length ÷ 8 ft spacing, rounded up, plus one end post. Pickets = fence length in inches ÷ 5.5 in picket width; rails = 2 per section.
How to estimate fence
- Posts are spaced 6-8 ft on center; closer spacing is sturdier on windy or sloped sites.
- For a privacy fence pickets butt tight; for a picket-style fence add a gap, which lowers the count.
- Add a third rail for fences taller than 6 ft. Set posts in concrete below the frost line.
- Confirm the property line and call 811 for utility locates before digging post holes.
- Buy a handful of extra pickets - a few always split or warp, and matching weathered wood a year later is hard.
Frequently asked questions
How many fence posts do I need?
Divide the length by your post spacing (commonly 8 ft) and add one for the final post.
How many pickets per foot of fence?
With 5.5 inch pickets butted tight, about 2.2 pickets per linear foot.
How deep should fence posts go?
A common rule is one-third of the above-ground height, with a 2 ft minimum and below the frost line - so a 6 ft privacy fence wants 8 ft posts set about 2 ft deep, deeper in cold climates.
How much concrete per post?
Figure one to two 80 lb bags per post for a typical privacy-fence hole; bigger holes and gate posts take more. Fast-setting mix poured dry into the hole and watered is the standard shortcut.
How soon can I build on set posts?
Fast-setting concrete can take rails in a few hours; standard mix is better left overnight. Racking a fresh post out of plumb is a mistake you live with for decades.
Do I need a permit for a fence?
Many towns regulate fence height (commonly 6 ft in back yards, lower in front) and placement near sidewalks and corners. A quick call to the building department is cheaper than moving a fence.