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Fence calculator

Fence calculator for posts, pickets, and rails.

Enter fence length, post spacing, picket width, and gap to estimate posts, rails, and pickets. A 100 ft run at 8 ft spacing needs about 14 posts and 209 pickets.

100 ft at 8 ft spacing

14 posts

209 pickets

Sections

13

26 rails total

Post spacing

8 ft

typical wood fence

Fence estimate

Fence calculator

Live estimate

Posts assume a straight run (one per section plus a closing post). Corners, gates, and end posts change the count. Need concrete for the post holes? Use the post-hole calculator.

Quick reference

Fence materials by fence length

Posts every 8 ft, two rails per section, and 5.5 in pickets with a 1/4 in gap, for one straight run.

Fence lengthSectionsPostsRailsPickets
50 ft7814105
100 ft131426209
150 ft192038314
200 ft252650418
300 ft383976627
What to measure
Fence elevation showing total length and post spacing Fence length Post spacing

Add a post for every corner and each side of a gate. Measure along the fence line, not the property diagonal.

Quick fence answers

Common fence lengths

50 ft side yard

8 posts

about 105 pickets

100 ft backyard

14 posts

about 209 pickets

150 ft yard

20 posts

about 314 pickets

Posts need concrete

Most fence posts are set in concrete. Take the post count here into the post-hole calculator with your hole diameter and depth for bags of concrete.

Shopping list

Posts, pickets, rails, and gates

Post and picket counts update from the calculator. Confirm post length, board size, and gate hardware before ordering.

Structure

14 posts

Fence posts

Use the post count as a starting point, then confirm post length for your fence height plus the buried depth and any corner or gate posts.

Infill

209 pickets

Pickets or panels

The picket count assumes the entered width and gap. Pre-built panels cover a section at a time and change how you buy.

Rails and base

Rails, concrete, and hardware

Plan rails per section, fast-setting concrete for the post holes, screws, brackets, and any post caps.

Access

Gates and hardware

Gates, hinges, latches, and gate posts are separate from the run length and often the trickiest part of the order.

Formula shown

How the fence estimate works

1. Sections and posts

sections = ceil(length / spacing); posts = sections + 1

2. Rails

rails = sections x rails per section

3. Pickets

pickets = ceil(length x 12 / (picket width + gap))

Straight-run assumption

The post count assumes one continuous straight run. Every corner, gate, and end adds posts, and panels or pre-built sections change how pickets are bought. Add posts for each gate and corner.

Sources

Sources checked

Written by

MeasureTwice Editorial

DIY estimating and home-improvement research

Checked against

Deck and fence layout rules and installed-cost ranges checked against published building and cost guides.

How we check our numbers

Last updated: June 25, 2026

Estimate only. This calculator is not a quote. Verify product yield, price, delivery minimums, and local conditions with your supplier or contractor before buying materials.

FAQ

Fence calculator questions

Posts, pickets, post spacing, and concrete for fence posts.

How many fence posts do I need? +

Divide the fence length by the post spacing (commonly 8 ft) and add one closing post. A 100 ft straight run at 8 ft spacing needs about 14 posts before adding corner and gate posts.

How many pickets do I need for a fence? +

Pickets depend on width and gap. For 100 ft of fence with 5.5 in pickets and a 0.25 in gap, that is about 209 pickets. Wider boards or larger gaps reduce the count; a butted privacy fence uses the most.

How far apart should fence posts be? +

Wood fence posts are commonly set 6 to 8 ft apart. Closer spacing is stronger and uses more posts; 8 ft is a typical maximum for a standard wood fence. Match the spacing to your rail length and local wind.

How much concrete do I need for fence posts? +

That depends on the hole diameter and depth, not the fence length. Estimate it with the post-hole concrete calculator using your post count, hole size, and depth.

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