Estimate posts, pickets, rails and concrete bags for any fence — with an optional cost breakdown.
Sections
13
Pickets
200
Calculator
Posts needed
14
Sections
13
Pickets
200
Rails
26
Fence posts
14
Sections
13
Pickets
200
Rails
26
Concrete bags
28
Material breakdown
Fence posts
14
Pickets
200
Rails
26
Concrete bags
28
How to estimate fence materials
Start with the number of posts: divide the fence length by the post spacing and add one for the final end post (round up if the spacing does not divide evenly). The number of sections is always one fewer than the posts. For a 100 ft fence on 8 ft centres you need 14 posts and 13 sections.
Pickets depend on the combined width of one picket plus the gap between pickets. Convert that sum from inches to feet and divide the fence length by it, rounding up. Rails multiply the section count by the rails per section — two rails suit most privacy fences; three rails are common for taller or heavier fences. Finally multiply the post count by the bags of concrete per post for the setting mix.
How far apart should fence posts be?
Most residential fences use 6 ft or 8 ft post spacing. Eight feet is the standard for privacy fencing because it matches the length of common lumber. Closer spacing (6 ft) adds strength for taller fences or soft ground.
How many bags of concrete do I need per post?
Typically 1–2 bags of 50 lb or 60 lb concrete per post. Use 2 bags for posts set deeper than 2 ft or in loose soil, and 1 bag for shallow decorative posts.
Do I need 2 or 3 rails per section?
Two rails (top and bottom) work for fences up to about 4 ft high. Three rails are recommended for 6 ft privacy fences because they reduce bow and better support the picket weight over longer spans.
Results are estimates. Verify with a professional for important decisions.
About this calculator
This calculator estimates the number of posts, sections, pickets, rails, and concrete bags needed for a fence of any length. Use it when planning a new yard fence, replacing an existing one, or pricing materials before hiring a contractor.
How to read your results
The headline figure is the number of posts your fence requires. Below that, the summary card lists sections (the spans between posts), pickets, and rails. The horizontal bar chart visualises these four material quantities side by side — the longest bar represents the material you need most, which is almost always pickets for a standard privacy fence.
Worked example
A 100 ft fence with posts every 8 ft, 5.5 in wide pickets with a 0.5 in gap, 2 rails per section, and 2 concrete bags per post.
14 posts, 13 sections, 200 pickets, 26 rails, and 28 bags of concrete.
Frequently asked questions
Why does the post count include an extra post?
A fence with n sections needs n + 1 posts — one at each end and one between every pair of adjacent sections. The calculator applies this rule automatically using the formula: posts = ceil(length ÷ post spacing) + 1.
How is the picket count calculated?
Each picket occupies its own width plus the gap between pickets. The calculator converts that combined width to feet and divides the total fence length by it, then rounds up to the nearest whole number so you never run short.
How many rails per section should I choose?
Two rails (top and bottom) suit most privacy and picket fences up to about 4 ft tall. Three rails are recommended for fences 5 ft or taller, or anywhere extra rigidity is required such as along a slope or in a high-wind area.
What determines how many concrete bags I need per post?
The standard recommendation for typical residential posts (4x4 in, set 2 ft deep) is 1–2 bags of 50 lb fast-setting concrete. Taller fences or looser soils may require 3 bags. Enter your expected bags per post and the calculator multiplies that by the total post count.
Can I use this calculator for non-picket fence styles?
Yes. For panel or rail fences where individual pickets are not applicable, set the picket width to the panel or board width and the gap to the spacing between boards. The post and rail counts remain accurate regardless of fence style.
How it's calculated
Post count is derived from the Inch Calculator fence methodology: posts = ceil(length ÷ postSpacing) + 1, and sections = posts − 1. Picket count is ceil(length ÷ ((picketWidth + gap) ÷ 12)), where widths are converted from inches to feet before division. Rail count equals sections multiplied by the number of rails per section. Concrete bag count equals posts multiplied by bags per post. All formulas align with the material estimation approaches published by Inch Calculator and Hoover Fence.
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