Fence Material and Post Centers Calculator

To estimate the amount of fence posts, rails, pickets, and hardware you need, enter your fence length, number of rails, and picket dimensions. You’ll also get a cost estimate for pressure treated wood, cedar, and redwood.

See below for information on various types of fences to help you and to learn how to calculate wood fence materials.


Material Estimate:

14 8' 4x4 posts
26 8' 2x4 rails
14 bags post concrete
3 lbs 3-1/2" screws/nails

Estimated Material Cost:

Pressure Treated: $344 - $512
Cedar: $614 - $782
Redwood: $884 - $1052
*Estimate only - costs vary by location/vendor, selected material, and quantities.

Installation Overview:

100 ft total length
14 number of posts
7' 8 1/16" between post-centers
2 rails per section
Estimated using the slip-board / estate fence style
See more fence styles

Compare to Vinyl:

The average cost of materials for a 100' vinyl fence is around $1000 - $2500
See a detailed 100' vinyl fence estimate

Pro Tip:

Post levels can make the job of installing fence posts much easier
Post Level
Don't Forget, you will need the following tools for your fence installation project:
Fence Post DiggerShovelDigging BarMason LineTape MeasureLevelCircular SawCordless Drill

How to Estimate Privacy Fence Materials

Fences are a great way to add privacy, security, and decor to your property. They can be constructed from a variety of materials including wood, metal, vinyl, and stone.

Interested in installing a vinyl fence? Our vinyl fence calculator can help calculate materials.

The type of material you choose depends on its purpose and the style you prefer. Wood fences are great for adding privacy and security and are commonly preferred for their style and affordability.

Get Free Project Estimates

Find Qualified Fence Professionals in Your Area

When building a wood fence, you’ll need to determine what lumber and hardware you need and how much of each. For most wood fences you need posts, rails, pickets, and nails or screws. You may also need gate hardware, post caps, stain or paint, lighting, or other materials depending on the style you choose.

Some concrete and the tools to mix and pour it will also be needed to set the posts. Use our post concrete calculator to estimate the amount of concrete you need for your fence posts.

How much material you need to build your fence depends on the style you want. Once you’ve chosen a style, you can enter your total length and rail and picket specs into the wood fence calculator above to get an estimated bill of materials.

The calculator will estimate how much lumber you need to construct your fence, including the number of posts, rails, pickets, concrete, and nails/screws.

Continue reading to learn how to make the calculations yourself.

Illustration of wood fence styles including solid board, shadowbox, stockade, and picket styles
The style of fence determines which materials are required for the project.

How Many Posts Are Needed to Build A Fence

The first step in figuring out how much wood is needed to build a fence is to measure the length. Given the total length, you can estimate the number of posts you need.

Posts are typically 8 feet apart. So, divide the length by 8′ and round up to get the number of sections. Then, add 1 to account for the last post.

For example, let’s find how many posts are needed for a fence with a planned length of 100 feet.

(length in ft. ÷ 8′) + 1 = posts
(100′ ÷ 8′) + 1 = posts
(12.5) + 1 = 13.5 posts

Round up to get 14 posts needed.

How Many Rails Are Needed to Build A Fence

To calculate rails, decide the number of rails you want. This will vary by the style and height of the fence, but there should be at least two. Multiply the number of sections by the number of rails per section to find the total rails needed.

The number of sections can be found by subtracting 1 from the number of posts in the previous step.

For example, let’s find how many rails will be needed for a 100′ fence with 14 posts. There will be two rails per section.

14 posts – 1 = 13 sections

13 sections × 2 rails = 26 total rails

How Many Pickets Are Needed to Build A Fence

To calculate pickets, decide the width and spacing of your pickets. Add the width and the spacing together to get the combined width.

Change the length of your fence to inches to match the picket measurements. Divide the fence length by the total picket width to get the number of pickets needed.

For example, let’s find the number of pickets needed for a 100′ fence using a 5- ½” picket with a 2″ spacing.

5.5″ picket width + 2″ spacing = 7.5″ combined width

100′ length ÷ 12 = 1200″ length

1200″ length ÷ 7.5″ combined width = 160 pickets

Tips For Estimating Fence Lumber

We recommend ordering 10% extra lumber to account for cutoffs and waste. Posts are commonly constructed using 4×4 dimensional lumber, and rails are often 2×4.

Plan on ordering lumber to build gates as needed, including additional posts and hardware. Gate posts are usually 4×4 or 6×6 dimensional lumber.

How to Estimate Fence Price

The average fence costs $2000 to $8000 to install, depending on material, style, and length. Wood is often chosen for its durability, aesthetics, and affordability.

To determine a solid price estimate, decide on the fence style and type of wood you want and accurately estimate the amount of material needed. Common wood choices are pressure-treated wood, cedar, or redwood, and they vary in price considerably. Use the calculator above to estimate quantities and costs for all three materials at once.

A home center or lumberyard can provide you with your local material costs. Ask for prices on 4×4s, 2×4s, and pickets in each wood you are considering. Also, get the price of exterior screws and post-setting concrete. Multiply the prices by the amount of material needed, then add them together to get a total estimated cost. We also suggest finding a local contractor to get a professional estimate for your project to find out precisely what it will cost.

Types of Lumber Needed For a Wood Privacy Fence

The types of lumber needed for a wood privacy fence will vary by it’s type and style. Some styles have two horizontal rails between the posts and others use 3, 4, 5, or more.

Most involve pickets—or sometimes rails—being placed so that they touch thereby blocking the view through the fence, while some have no pickets at all. Several of these styles are discussed below.

Estimate Solid Board Privacy Fence Material

A solid board privacy fence consists of 2 or 3 rails connected to posts with attached pickets that have no gaps between them. Pickets are usually 5-½” wide (thinner pickets are called “stockade” style; see below).

All of the pickets are installed on the one side of the rails. So, you can see the rails on one side of the fence but not the other. The rail side is usually installed facing in. The other side is smooth and is usually public facing.

The exception is the framed style where the rails are located at the very top and bottom to “frame” the pickets. These rails are usually public facing. See popular solid board styles.

Use the following values for the form above to estimate:

  • Length: fence length
  • Rails per Section: 2 or 3
  • Picket Spacing: 0
  • Picket Width: 5.5″

See popular solid board styles.

Estimate the lumber needed to build a solid wood fence
Illustration showing the picket, rail, and post layout for a solid board fence.

Estimate Shadowbox Fence Material

A shadowbox fence is similar to the solid-board style except the pickets are installed on both sides of the rails with a gap between them. The pickets from one side are spaced so that they cover the space between the pickets from the other side. This creates a solid visual barrier.

Because pickets are mounted on both sides, the shadowbox style looks the same on each side.

Use the following values for the form above to estimate:

  • Length: fence length
  • Rails per Section: 2 or 3
  • Picket Spacing: -1″
  • Picket Width: 5.5″
Estimating lumber for a shadowbox style fence
Illustration showing the picket, rail, and post layout for a shadowbox fence.

Estimate Stockade Fence Material

A stockade style fence is identical to the solid-board fence except that 2-½” to 3-½” wide pickets are used to achieve the stockade look. Just like a solid-board fence, you will want to consider on which side you want the railings to show.

Use the following values for the form above to estimate:

  • Length: fence length
  • Rails per Section: 2 or 3
  • Picket Spacing: 0
  • Picket Width: 2.5″
Estimating parts for stockade fence
Illustration showing the picket, rail, and post layout for a stockade fence.

Estimate Picket Fence Material

A spaced picket fence consists of posts with 2 rails and 2-½”-wide pickets that are spaced evenly with a gap. The gap is usually the width of a picket, though this can vary. All pickets are installed on the same side of the rails, typically on the public-facing side. There are many patterns for picket styles and spacing. See popular picket styles.

Use the following values for the form above to estimate:

  • Length: fence length
  • Rails per Section: 2 or 3
  • Picket Spacing: 3.5″
  • Picket Width: 3.5″
Estimating parts to build a picket fence
Illustration showing the picket, rail, and post layout for a picket fence.

Estimate Slip-Board Fence Material

A slip-board or estate fence consists of posts with 2, 3, 4, or more rails and no pickets. Traditional slip-board fences have three rails and are often constructed of unhewn, natural materials. Slip-board fences can also be built using dimensional lumber like those commonly seen for fencing horses. You may want to consider trying round posts and railings, tree saplings as rails, or using different sized boards to achieve different styles.

Use the following values for the form above to estimate:

  • Length: fence length
  • Rails per Section: 3
  • Picket Spacing (inches): 0
  • Picket Width (inches): 0
Estimating parts to build a slip-board fence
Illustration showing the picket, rail, and post layout for a slip-board fence.
Next Step – After estimating materials, it’s time to begin laying things out. Learn how to lay out a fence safely and efficiently, including how to avoid buried utilities, center your posts and panels, and get perfectly square corners.

Before you begin your fence project be sure to read our pro tips that will help you through the process.

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