How Much Decking Do I Need? How to Use a Decking Calculator

Decided to add a deck to your garden space?


You’ll have lots to look forward to, from BBQs in the summer to stargazing in the winter. However, before we get into all that, it’s time to build the thing. And you’re here because you’ve realised that it can be easier said than done. Between finding a decking calculator and selecting balustrades (or not), you can find yourself tired of decking before you’ve so much as lifted a hammer.

Never fear! We’ve put together a foolproof guide explaining how you can find out exactly what you need. No waste, no hassle, just the materials to build the deck of your dreams.

Let’s get started!

decking calculator - planning your deck

Planning your Deck


If you have already planned exactly what space your deck will occupy, then skip right on down to our decking calculator section of this blog.

If you’re still gazing at the garden with more than a little sense of fear at how big the task seems, then don’t worry. Take a breath, and we’ll keep it simple.

Here is what you need to consider, before you can start measuring and calculating:

  • Will my deck be an extension of my house, or will it stand alone?
  • Is the ground already level, or do I need to fix that first?
  • What am I going to use my deck for? If it’s sunbathing, don’t put it below a tree. If it’s to get peace and quiet from the house, then put it a little further out from your home.
  • Will my deck need stairs, and how will it be accessed? Is there room for access in the spot I have planned?
  • Are you going to DIY? Or get someone in to help out?
  • What material are you building on? If your soil is very weak, sandy or subject to flooding, then get in touch with a professional for tailored advice.
  • What type of material do you want to use? Wood is not the only option out there. You could go for a composite material, or a pressure-treated wood.

Phew! Once you’ve had the chance to think about all these points, you are ready to dive into the next part, which is our decking calculator.

Still with us?

Great. Read on!

decking calculator - how to plan your decking

Decking Calculator


The easiest and most accurate way to figure out how much decking you are going to need, in our humble opinion, is to use our decking calculator.


Because it is worked out by actual humans, and not a computer, and so we will take into account actual human things like adding in the cost of delivery and whether or not you need steps.

If you are new to building decking, then you will find the calculator useful for making sure that you have actually covered all your bases and thought of everything you are going to need before you start buying in the supplies.

Here’s what you’ll need to decide before you fill out the decking calculator:

  • The length and width of the decking space
  • The direction of the timber planks
  • The size of the individual deck boards
  • If your deck is raised or ground level
  • The type of balustrade you would like
  • Whether or not you need a gap in the balustrade for entrance/exit, and steps if it is raised

Got all of that ready?

Once you have filled out the info, it will go straight to one of our in-house experts. You will then receive a no obligation quote to help you make your decking decisions.

Depending on what quote you get, you might then choose to change your requirements or try a different style of decking, and please do! We are more than happy to help.

If you’re designing a deck which isn’t a typical shape or size, then again, please do just get in touch.

Have you found this information helpful? Is there a deck-planning step that you think we’ve missed? Let us know in the comments!


Now, where did we put that decking calculator ..?

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