Composite Decking Calculator: How to Get a Near-Accurate Estimate

Having a beautiful deck which can enhance the beauty of your lovely home and also its market value. Composite decks are a favorite of many homeowners, not just in Australia but also over the world. Wood is the most favorite choice, with, of course, an array of other materials as an alternative, the possibilities are exciting in the world of composite decks. The trick of creating a staggering design lies in the fact that the deck is built accurately and here comes the role of composite decking calculator. These calculators help in calculating the exact requirements of the material.

There are some highly advanced decking calculators which take into account the heights as well hence ensuring precise calculation. You can easily find these decking calculators online, or else you can also rely on decking suppliers. They have the necessary manpower who ensure that you are able to get the right estimate of project and supplies. Therefore, it is no wonder that there is a lot of curiosity about composite decking calculators. While generic calculators can give you a vague about the price range in the neighborhood of which it is going actually to cost you, they are nowhere near accurate. So, in this article, we will give you four easy steps in which you can estimate how much it is going to cost you to get the composite deck that you need to build.

Ditching the composite decking calculator and using manual way to install deck-

Step 1

Measure and calculate the dimensions of the desired deck

Step 2

If you would fancy any deck steps, make an account of them for an accurate estimation.

Step 3

Further, if you would like to add benches or raised planters, it is a good idea to do that, so further streamline your estimated costs

Step 4

Choose the board that would like. There are various options like Granite, Walnut, Oak, Silver Birch, Stone, Iroko, Teak, Slate, Marble, to choose from. If you are going for diagonally aligned boards, it is a good idea to factor in an extra 15% materials, due to wastage because of the orientation.

After you follow these steps, you can easily calculate the total costs.


Planning and process

A comprehensive plan will ensure that you order just about enough material, so that you save money on multiple deliveries, and also the time. Ordering more as an afterthought is not financially prudent. Add an extra 5% for wastage of the material.


Once you have got the estimate, you can place the order for the deck supplies, but on arrival the decks must be stored in a certain manner such that it doesn’t affect their luster and texture. The boards for the composite decks, when they arrive, have to be stored flat and covered, with supports at 50cm intervals. The boards need to be handled with care. They need to be carefully picked up and placed and not slid and dumped. The boards are easy to carry on the edges.

Positioning the deck

By this point, you have the location of the deck. Use the 3-4-5 Rule the deck can be positioned. How do you do it? Here’s how:

Stalk a line 4m long, parallel to the wall or the surface, the deck will run straight with it. One end of the stake will be point A, while the other end of the stake will be point B.

Go back to point A and connect a second line which is perpendicularly up to the point where the third point is 3m. This point is stake C. So, we get the right angle, and the distance between B and C is 5 m. This is called a 3-4-5 triangle decking installation.

Another point to take into account while installing a deck is to see that there is proper drainage. There should be no flex in the substructure. You got to have joists that are supporting the deck. The beams should be 30 cm apart. You have to drill 3mm holes for the screws in all the composite products. Make sure the gaps and the joists are spaced correctly. Use decking starter fasteners and line up the first board with perfection and speed, and then follow the rest. Use the decking hidden fasteners to secure them fast. This process if appropriately followed, will get you a nice, seamless finishing touch. The benchmark is to have no visible screws across the deck.

decking calculator

A power mitre saw can be used for speed and accuracy of installation. Special care has to be taken when trimming the edges of the decks so that no damage is caused to the deck boards.

The steps mentioned above can help you in understanding the process of setting up a composite deck, even if you don’t do it all yourself, but enlist professional help.

What should you know before using composite decking calculator?

  1. Pen down what needs to be calculated
  2. Now you need to start measuring it, if you are not sure of calculation yourself, then you need to use composite decking calculator.
  3. These calculators have various parameters like length, width and even height, some also have the provision of stairs. With these features calculating the decking requirement becomes easy and accurate.
  4. With the right calculation, you would be able to find out the total pricing of installation.
  5. You must know that the average size of a small deck is 12 feet by 12 feet.
  6. The composite decking calculators are easy to use and hence are able to give you the right estimate of the decking supplies.


The above-mentioned tips and guidelines can be used to get an estimate of the deck. You can either opt for manual calculation or else you can also go with the online composite decking calculator. Both these methods are good and have their own benefits, however online composite decking calculator makes the task very easy.

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