Omni calculator
Last updated:

Fence Estimate Calculator

Table of contents

Using the fence estimate calculatorMore fence-related calculatorsFAQs

There's no need to keep guessing; with Omni's fence estimate calculator, you can get a good estimation of how much fencing material you need to build your fence.

Renovation projects can be stressful situations, especially if you don't know where to start or are working on a limited budget. Knowing beforehand how many posts, pickets, and concrete you'll need to build a fence can help you plan, make smart money decisions, and save money and time!

Continue reading to learn how much material you'll need to complete the fence, and also figure out:

  • How to use this tool;

  • How many feet of fence for a 1/2 acre field you need; and

  • How much concrete for a 4x4 fence post you need.

Using the fence estimate calculator

Fence estimate calculator: fence parts.

The fence estimate calculator can be a great tool to help you save time and money when planning to build a fence. It allows you to quickly estimate the amount of material you need. Let's go through how to use this tool!

But before we begin, you need to know the dimensions of your yard or the total length of the fence you want to build. If you don't have these measurements just yet, it's time to go outside and measure. Don't worry; we'll be here waiting for you 😉 If you already have your measurements, let's move on to see how to use this tool:

  1. Begin by entering the Fence length and Post space. This last one is set as 2.5 meters as default, but typically, the post space is anywhere between 6 and 8 feet; or 2 and 5 meters, depending on your preference.

  2. With this information, the calculator will display the Number of posts and Number of sections.

  3. Next, input the Fence height, and the calculator will show the Post length. Notice that at least 1/3 of every post should be buried in the ground and secured with concrete.

  4. Now indicate the Picket width and Picket spacing. Pickets' width is often between 3 1/2", 5 1/2", or up to 11 1/2". Typically, picket spacing is 2 1/2", but it can also vary anywhere between 1" to 6".

  5. The calculator will indicate the number of pickets.

  6. Finally, you can determine the volume of concrete you need for post footing. For this, you need to enter either the diameter of your post for cylindrical posts or the width and thickness of the post for cuboid posts.

Fence estimate calculator: post measurements needed for concrete hole.

How much concrete for a 4x4 fence post do I need?

You need 4608 in3 of concrete for one 4x4-inch post in a 6 ft tall fence. To obtain this value:

  1. Use the following formula:

    volume_of_concrete = (hole_volume - post_volume) × number_of_posts

  2. To obtain the hole_volume:

    hole_volume = (3×post_width) × (3×post_thickness) × (1/2×fence_height)

    hole_volume = (3×4 in) × (3×4 in) × (1/2×6 ft) = 5184 in3

  3. Determine the post_volume:

    post_volume = post_width × post_thickness × (1/2×fence_height)

    hole_volume = 4 in × 4 in × (1/2×6 ft) = 576 in3

  4. Substitute these results in the volume_of_concrete formula:

    volume_of_concrete = (5184 in3 - 576 in3) × 1 = 4608 in3

How many feet of fence for a 1/2 acre do I need?

You need a minimum of 590.32 ft of fence for a 1/2 acre. Since acres are a measure of area, the exact amount of fence you need depends on the shape of the land:

  • For a squared fence, you need 590.32 ft. This corresponds to a 147.58 ft × 147.58 ft area.

  • For a rectangular fence with a length that's twice the width, you need 626.13 ft. This is a 104.35 ft × 208.71 ft area.

How do I calculate the number of fence posts needed?

To calculate the number of fence posts that you need:

  1. Use the following formula:

    Number of posts = (fence length / post spacing) + 1

  2. Typical post spacing is between 6 and 8 ft, or 2 to 3 m.

  3. Make sure to convert all lengths to the same unit.

  4. Round the result to the next whole number.

For example, for a 300 ft fence with 7 ft post spacing:

Number of posts = (300 ft / 7 ft) + 1
Number of posts = 43.86
Number of posts ≈ 44

parts of a fence

Number and length of posts needed

Number of rails needed

Number of pickets needed

Concrete for post footing

To calculate the volume of the concrete, we need to know the volume of the post. Hence the need for the post's exact measurements.

Visit the cement calculator to determine how much cement, sand, gravel, water, or money you'll need for this concrete volume.

Check out 28 similar home and garden calculators 🏡
Air changes per hourAir conditioner BTUArch...25 more