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Fence Calculator

Plan a wood fence by working out the number of posts, rails and pickets you need. The calculator also counts gates and estimates the concrete for the posts.

Your measurements

ft
ft
in
in
count
ft
%

Fence pickets needed

211pickets

Fence sections
12
Posts
14 (about 8 ft long each)
Rails (8 ft)
36
Concrete (50 lb bags, about 2 per post)
28 bags

Posts include one extra per gate. Post length assumes about 2 ft underground; set posts deeper below the frost line.

How to use this calculator

  1. Enter the total length of fence, including any gates.
  2. Choose the post spacing. Eight feet is common, and six feet makes a stiffer fence.
  3. Enter the fence height, picket width and the gap you will leave between pickets.
  4. Pick two or three rails per section. Taller fences usually use three.
  5. Enter the number of gates and their width.

How the numbers are calculated

Gate widths are subtracted from the total length. The remaining run is divided by the post spacing and rounded up to get sections. Posts equal sections plus one, plus one extra post for each gate.

Pickets are the run in inches divided by the picket width plus gap, with waste added. Rails are sections times rails per section. Concrete assumes about two 50 pound bags per post. Post length is the fence height plus about two feet underground.

Worked example

A fence 100 ft long with one 4 ft gate has a 96 ft run. With 8 ft spacing that is 12 sections, 14 posts and 36 rails. With 5½ inch pickets and a ¼ inch gap, 5% extra gives 211 pickets. Concrete is about 28 bags.

Tips before you buy

  • Set posts about one third of their length into the ground, and at least 24 inches. Go deeper where the ground freezes.
  • Check property lines, local height limits and any homeowners association rules before you build.
  • Call your local utility locate service before digging.
  • Use pressure-treated lumber rated for ground contact for posts.
  • Slope or uneven ground changes the picket count. Step the sections down the hill and add some extra.

Frequently asked questions

How far apart should fence posts be?

Six to eight feet is the standard range for wood fences. Eight feet uses fewer posts, while six feet gives a stronger fence.

How deep should fence posts go?

A common rule is one third of the post length underground and at least 24 inches. In cold climates, set them below the frost line.

How many pickets per foot?

With 5½ inch pickets and no gap you need about 2.2 per linear foot. A small gap lowers that a little.

How many bags of concrete per post?

Roughly two 50 pound bags per post for a standard hole. Larger posts or soft soil may need more. Check the bag label for coverage.

Related calculators

These results are estimates for planning purposes. Material sizes, densities and local requirements vary, so confirm quantities with your supplier or a qualified contractor before ordering.

Last updated October 11, 2026.