Fence calculator: fence parts
Number and height of posts needed
Fence length
Post space
Number of posts
Number of sections
Fence height
Post height
Number of rails needed
Rails per section
Number of rails
Number of pickets needed
Picket width
Picket spacing
Number of pickets
Concrete for post footing
Post shape
Post width
Post thickness
Concrete volume
cu yd

This fence calculator will be of great use to you if you want to build a fence on your own. Use it to plan your work by estimating the correct amount of fencing materials that you will need to complete your privacy fence project. Thanks to our fence estimator you will know exactly what to buy and how much of it you need, which will answer a pressing question on your mind, how much does a fence cost?

How to use the fence calculator?

Fence calculator: fence parts

Although our fence estimator may seem complicated at first, in reality it is quite a simple tool. Read this short set of instructions to learn how to use it.

  1. Start by deciding how long is your fence going to be and how much space you want between posts. Typically, the post space is somewhere between 6 and 8 feet; or 2 and 5 meters, depending on your preference. Put the fence length and the space between posts in the first section of the fence calculator and it will return both the number of posts you should buy and the number of sections defined by the number of posts, which is a value we will need later on.

  2. Put in the height of the fence in order to see the length of the posts you need to buy. That is important because at least ⅓ of every post should be buried in the ground and secured with concrete.

  3. Put in the number of horizontal rails per section of the fence. Two rails per section is the most common number, but it depends on the style of the fence. You will then get the total number of rails you need to buy. A rail is the same length as a section.

  4. Put the width of a single picket and the spacing between the pickets in the third section of the fence calculator in order to determine the total number of pickets.

  5. As every post needs to be secured so that your fence doesn't fall over, you need to put the posts in holes filled with concrete. In order to calculate the volume of concrete needed to do that, input either:

  • the diameter of your post for cylindrical posts
  • the width and thickness of the post for cuboid posts

Fence calculator: post measurements needed for concrete hole

Equations used in the fence calculator

If you want to know how we calculate the amount of fencing materials you need, here is a list of the equations we used:

  • Number of posts = (fence length / post spacing) + 1 (round the result up)

  • Number of sections = number of posts - 1

  • Post length = fence height * 1.5

  • Total number of rails = number of rails per section * number of sections

  • Total number of pickets = fence length in inches / (picket width + picket spacing) (round the result up)

  • Volume of concrete = (hole volume - post volume) * number of posts

  • Cuboid post volume = post width * post thickness * height of the buried part of post

  • Cuboid hole volume = (3 * post width) * (3 * post thickness) * height of buried part of post inches

  • Cylindrical post volume = post radius² * height of the buried part of post * π (radius = ½ of post diameter; height of the buried post = ⅓ of the post length)

  • Cylindrical hole volume = (3 * post radius)² * height of the buried part of post in inches * π

Using the fence estimator - example

To make the process of estimating fencing materials even clearer, let's go through an example together.

Let's say we want to build a fence that's 1,000 feet long, with 7 feet in between each post and a height of 10 feet. We will start by calculating the number of posts and how long they should be:

Number of posts = (1,000ft / 7ft) + 1 = 142.85 + 1 = 143.85

As we need to round the number up, the number of posts is 144. This gives us 143 sections.

Post length = 10ft * 1.5 = 15ft

Let's say we want our fence to have 4 rails per section. In this case, the total number of rails we need is:

Number of rails = 4 * 143 = 572

Now let's move on to the pickets. Let's say our fence will be built out of 5-inch-wide pickets, with 1 inch of spacing. As 1,000 feet equals 12,000 inches, the total number of pickets will be:

Total number of pickets = 12,000in / (5in + 1in) = 12,000 / 6 = 2,000

All we need to do now is to estimate how much concrete we will need to secure the posts to the ground. Let's say we are using cuboid posts that are 5 inches wide and 4 inches thick. Remember to change the height of the post into inches for this calculation - 15 feet equals 180 inches. ⅓ should be buried in the ground, so the height of the buried part will be 60 inches. First we need to calculate the volume of the part of the post that's underground with the cuboid post volume equation:

Post volume = 5in * 4in * (1/3 * 180in) = 20in² * 60in = 1200in³

Next, we calculate the volume of the cuboid hole:

Hole volume =(3 * 5in) * (3 * 4in) * 60in = 10,800in³

Now all we need to do subtract the post volume from the hole volume and multiply the result by the total number of posts.

Total volume of concrete needed = (10,800in³ - 1200in³) * 144 = 1,382,400in³‬

Concrete is usually given in cubic yards, so after conversion, we see that we will need 29.63 cubic yards of concrete.

Thanks to our calculations, we now know that, if we want to build our 1000-feet-long, 10-feet-high fence, we will need to buy:

  • 144 15-feet-high posts,
  • 572 rails,
  • 2,000 pickets,
  • and 29.63 cubic yards of concrete.

A tip for buying fencing materials

Even professional construction workers are bound to make mistakes sometimes. After all, we are only human. Always keep a mistake margin in mind. It is generally recommended to buy about 10% more fencing materials than you actually need, in case you need to correct a mistake. If your fence ends up perfect on the first try, the additional materials won't go waste anyway - you will have them ready for any future repairs. If you need help calculating the extra 10% of fencing materials needed, you can use our percentage calculator.

Why have a privacy fence around your property?

You might wonder why you should even bother building a fence. There are a number of reasons why having a fence around your property is a good idea:

  • Privacy. As the name itself suggests, a privacy fence will allow you to relax in your garden, without having to worry about any prying eyes.

  • Protection. A privacy fence will not only keep your children and pets within a safe area, but also will keep stray animals out. It will serve as a great windbreaker too, allowing you to enjoy your time outside without having to worry about wind chill.

  • Decoration. Your privacy fence can enrich the look of your garden. If you want your garden as beautiful as possible, consider using some of our gardening calculators to calculate plant spacing, as well as the amount of soil and mulch you need.

  • Noise isolation. If you live close to a street or some facility that produces a lot of noise pollution, a privacy fence is one of the easiest ways to deal with it.

  • Tradition. While this may not be an entirely serious reason, the fact remains that to many, a nice white picket fence around your property symbolizes achieving the American Dream.

Fence calculator: a white picket fence - the epitome of the American Dream

Why build a privacy fence on your own?

There are a number of reasons why you should consider building a fence on your own rather than getting a contractor to do it for you. Here's just a few:

  • It's cheaper. By using this fence calculator to find out the amount of fencing materials you need, you don't need to buy anything else! With no construction workers or designers to pay, you can save loads of money.

  • You're free to do it the way YOU like it. As long as you have all the right permits, you are the only one you'll have to answer to regarding the fence's look. No one will try to convince you to do it in a way that's more "fashionable" or tell you how to build a fence that they think would be better (not including your other half).

  • It's satisfying. Building a fence may not sound like a very enjoyable activity at first, but here's the thing about DIY - it can give you immense satisfaction. Creating something with your own hands rather than getting it done for you can be an enriching experience, and the pleasure of a job well-done will come back to you every time you see your finished project.

  • It's something you can be proud of. To build something on your own requires a lot of skill. In this case, you need to know how to build a fence, calculate how much does a fence cost & the amount of fencing materials you need, and, most importantly, do the actual handiwork yourself. Learning to do all these things is definitely a reason to proud be of yourself.

  • It's healthy. After all, building a fence is a physical activity, and, as long as you are in good health, there is no such thing as too much of that. While building a fence, you will also get to spend time outside.

Saving on DIY house renovation

Are you keen on saving money and enjoy DIY? Learning how to build a fence is not the only thing you can do. There are many other projects you can do by yourself, and we have a number of tools other than this fence calculator which you may find useful. Consider, for example, painting your walls to give your place some fresh energy. Try using our paint calculator to make sure you get the right amount of paint, and enjoy a rewarding, creative activity. Another quick and easy way to do that is to decorate your walls with wallpaper - check how much wallpaper you need and go looking for the perfect pattern in your local store. If you already have some experience in house renovation, you can even consider tiling your floors on your own.

Maria Kluziak
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