Estimate the materials for a straight run of wood or vinyl fence. Enter the total length and post spacing to get the number of posts, sections and rails, and the picket width and gap to count pickets.
For fences with corners or gates, add an extra post at each corner and a post on each side of every gate.
Formula
Sections = ⌈Length ÷ Post spacing⌉ · Posts = Sections + 1
Pickets = ⌈Length ÷ (Picket width + Gap)⌉ and Rails = Sections × Rails per section.
Worked example
100 ft of fence with posts every 8 ft needs ⌈12.5⌉ = 13 sections and 14 posts. With 2 rails per section that is 26 rails, and 5½-inch pickets with ½-inch gaps need 200 pickets.
Frequently asked questions
How far apart should fence posts be?
Usually 6–8 ft (1.8–2.4 m) for wood fences. Vinyl and pre-made panels have a fixed spacing set by the panel width.
How many rails does a fence need?
Two rails for fences up to about 5 ft tall, and three for 6 ft privacy fences to stop pickets from warping.
Last updated · Calculations checked by automated tests· Editorial policy