Fence Calculator
A fence needs one post every 8 feet plus one, rails for each section, and pickets across the run. Enter your fence length and style to get posts, rails, pickets, concrete, and cost.
How to estimate fence posts and sections
Divide the fence length by the post spacing — 8 feet is standard for wood — then add one post to close the final section, plus an extra post for each gate opening. Subtract gate widths from the run so you do not buy pickets for the gaps.
Rails and pickets
Each section carries 2 rails for a 4-foot fence or 3 rails for 6 feet and taller. Pickets are counted across the fenced length: divide the run in inches by the picket width plus any gap. Turn off pickets for a post-and-rail or ranch fence.
Concrete and cost
Each post is set in 1–2 bags of concrete. The cost output totals posts, rails, and pickets — add concrete, fasteners, and gate hardware separately. Building a deck behind the fence? See the deck cost calculator.
Frequently asked
How many fence posts do I need?
Divide the fence length by your post spacing — usually 8 feet — and add one for the end post, plus an extra post per gate. A 100 ft fence with one gate needs about 14 posts.
How many pickets do I need for 100 feet of fence?
Divide the fenced length in inches by the picket width plus any gap. At 5.5 in pickets with no gap, 100 feet needs roughly 210 pickets.
How much concrete do I need per fence post?
Plan on one to two 50 lb bags of concrete per post for a standard residential fence. Taller or windier fences need more.