Fence Calculator: How many fence panels do you need?

Use this calculator to determine the number of posts, sections, rails, and pickets for your fencing project, as well as the height of the posts and amount of concrete needed. Provide a few specifications and let the calculator do the rest!

1. Length of Fence

The first step to any fencing project is to ​determine the length of your fence​ and the ​distance between posts​. The distance between posts is usually between 6 and 8 feet.

Also, you need to ​determine the height of your fence​ in order to calculate the proper height of the posts.

2. Number of Rails

Rails provide stability and keep your pickets in place. Most fences use 2 rails per section.

3. Picket Specifications

The ​width of your pickets​ and ​space between each picket​ will determine how many pickets are needed for your project.

4. Concrete for Posts

Each post needs to be cemented into the ground with concrete.

• At least 1/3 of each post should be underground.
• For cuboid posts, you will need the width and thickness of the post.
• For cylindrical posts you will need the post diameter.

Equations used (all measurements should be converted to feet)

• Number of posts = (fence length / space between posts) + 1 Note: round up
• Number of sections = number of posts - 1
• Post height = fence height * 1.5
• Number of rails = number of rails per section * number of sections
• Number of pickets = fence length / (picket width + picket spacing) Note: round up
• Volume of concrete = ((hole volume - post volume) * number of posts) / 27 (divide by 27 to get cubic yards)
• Cuboid hole volume = (3 * post width) * (3 * post thickness) * height of buried part of post
• Cuboid post volume = post width * post thickness * height of the buried part of post
• Cylindrical post volume = post radius² * height of the buried part of post * π
• Cylindrical hole volume = (3 * post radius)² * height of the buried part of post * π

How to Estimate a Fence Quote

1. Decide on the specifics of the fence. Typically, wood fences are 4 or 6 feet tall.

Also, decide how large of a fence you want and measure off the area using a tape measure. This should be expressed in feet.

2. Determine how many sections you need to complete the fence.

Typically, if you were constructing a fence that was 160 linear feet, you would need 20 sections. Remember, you will likely be adding at least one gate to this fence.

3. Make a materials list.

For every 8-foot fence section, which is standard for wood fences, you will need two or three 2x4 rails and 16 6-inch wide fence pickets.

Further you will need one 4x4 post for each section, plus an additional post.

If you use three 2x4s, you will need 96 screws or nails to complete a section.

These screws or nails should be an inch to an inch and one quarter long. Longer ones, such as 3 inches or slightly longer, will be needed to attach the 2x4s to the 4x4s. You will need four to six of these longer ones per post.

4. Price the lumber and fasteners and multiply the price of lumber, which includes your posts, rails and fence pickets, by the number you need. This will provide you with a fairly accurate measure of your materials cost. Screws and nails are often supplied by the box.

5. Check concrete prices.

Many people prefer to use one bag of concrete per post. Others go every other post, and some may elect for concrete only at the corners. No matter what method you choose, price accordingly.

How Many Fence Posts to Use

1. Determine the exact placement of the fence.

Walk around the property and examine the layout. Keep in mind that sudden dips or rises will disturb the structure. Mark the entire fence line with a dotted line using the spray paint.

2. Determine the placement of any gates or corners. Mark those spots with an "X" using the spray paint.

Lay out the 100-foot tape measure along the fence line using a gate post or corner as a starting point. Spray an "X" across the dotted line every 8 feet. Any "X" marks already in place for gates or corners that are within 8 feet of the previous mark can take the place of any new "X."

3. Count the number of spray-painted "X" marks. This is the ​total number of fence posts you will need for the project​. The layout is complete and ready for construction of the fence to begin.