If you want to give your garden a new lease of life this summer, decking is a fantastic way to make the most of your outdoor space. But before you get started, you'll need to know how many decking boards to buy – particularly if you plan on laying the decking yourself.
While the answer will depend on a variety of factors – such as the type of material and the size of the gaps between each board – there is a simple way to estimate a rough number, as our decking expert reveals below.
To find out how to make an approximate calculation, accurately measure your garden, and where to buy the best decking supplies, keep on reading – we've covered everything you need to know.
Article continues belowHow many decking boards do I need?
To work out how many decking boards you'll need in your garden, Jack Williams, founder of JPW Fencing and Decking, recommends using the simple formula below:
Decking width ÷ decking board width + 5% for wastage
Alternatively, you can estimate two boards per square metre when using standard 3.6m-long, 150mm-wide decking boards, according to Allan Jeffrey, commercial director of Ultra Decking.
This calculation will help you get a rough idea of how many decking boards to buy. However, you may want to speak with a professional installer for a more accurate estimate of your specific space – particularly if you're working with an awkward shape.
Where to buy decking supplies
This budget-friendly decking costs just £2.50 per square metre and has been pressure-treated to resist rot.
Get an accurate measurement of your decking area with this smart laser tool, which features an integrated memory for up to 10 areas.
Durable, anti-slip, and reversible, these composite decking boards are built to stand the test of time in your garden.
Jack Williams is the founder of JPW Fencing, a Bristol-based company specialising in landscaping services. He has more than 10 years of experience working with timber and composite decking, patios, fencing, garden houses, and more.
With over 40 years in product design and development, Allan Jeffrey set out to make high-quality composite materials affordable for every UK homeowner. Since launching his first collection, he has led the way in combining durability with style, offering authentic surface textures and market-leading stability – all at a price that makes sense. Today, Allan remains hands-on, personally reviewing every product, guide, and resource to ensure you get lasting quality and real support.
How do I measure my decking area accurately?
Now you know how to calculate the number of decking boards you need, your next question is probably how to work out the decking area. To do that, Allan Jeffrey says to measure the length and width of the space.
If you’re building a raised deck, you’ll also need to measure how high you want it to sit off the ground. It will be supported either by posts set into the ground (for soft surfaces) or by pedestals for hard surfaces like concrete.
While it’s definitely possible to work out an approximate calculation online, Allan Jeffrey says that for the most accurate results, it’s best to speak with a professional decking installer who can tailor it to your garden.
For more expert advice on installing your dream decking, read our guide on how to build a raised deck and whether you should choose wood decking vs composite.
