UK Decking Calculator Tool

Calculate softwood, composite, Walksure and Thermowood boards

Use our interactive decking calculator tool below to calculate how much decking you need to buy to complete your project.


  1. Select the type and size of decking you'd like from the drop-down menus.
  2. Enter the length and width of your planned decking area. If you are planning several decking areas, use the 'add area' button to calculate how much decking you need for extra areas.
  3. If required, you can adjust the amount of waste you'd like to include in the calculation. Our recommendation is to account for 10% waste.
  4. Scroll down to see your results. You can also download these in a printable PDF format.

Whether you are planning to design and build a new deck or rejuvenate an existing area, it's worth weighing up the pros and cons of the various deck board finishes and range of balustrades available.

With a variety different decking board options to choose from, Metsä Wood provides the widest range of decking available on the market, available from selected merchants nationwide. Whether you choose traditional slow-grown softwood, composite, Walksure or Thermowood decking, you can be assured our timber is fully certified and of the highest quality. See our full range of decking and balustrades to find out more.​​

Planning a flooring or cladding project?

Calculate how much flooring or cladding you need to buy with our other interactive calculator tools.