BuildCalc

Fence Calculator

Enter the total length of the fence and your post spacing (8 ft is common). The calculator returns posts, rails and pickets so you can build a materials list.

Your measurements

ft
ft
in

Layout

Sections
15 sections
Post spacing
8 ft

Materials

Rails
30 rails
Pickets
262 pickets

Fence posts

16 posts

Estimates only. Order a little extra for waste and verify against your supplier's coverage figures.

The formula

Posts = (Length ÷ spacing) + 1   ·   Sections = Length ÷ spacing

Example: A 120 ft fence at 8 ft spacing = 15 sections, 16 posts, ~30 rails.

How it works

  1. 1Divide total length by post spacing to get the number of sections.
  2. 2Posts = sections + 1 (you need a post on both ends).
  3. 3Rails = sections × rails per section; pickets = length in inches ÷ picket width.

Frequently asked questions

How much concrete do I need per fence post?

Plan for 1–2 × 50 lb bags of fast-setting concrete per post for a typical 4×4 in an 8–12 in wide hole, one-third of the post buried.