Composite Decking Calculator

We've created these handy calculators to take the guesswork out of the ordering. If you need any help estimating your project or would like us to prepare a free quote for you. Please contact our expert team on +353 1 447 0406 or at

How to manually calculate your decking

  • A drawing to scale may help you determine how much more material will be required
  • It is recommended that you add at least 5% to the total material required for a wastage factor. It is unlikely you will use the board lengths perfectly
  • For
    diagonally laid decking
    it is recommended that you add 15% extra material as you will generate more scrap from cutting.
  • If you do not want butt joints across the deck and the width is no greater than 2.8m, then you need to ensure you order enough extra 4m boards to cover the area
  • For multiple decking areas, follow the steps and sum the quantities together
  • Always round up the number of boards required

Step 1

Start off by measuring the width and length of your proposed decking area(s)

Step 2

Plan which direction to lay your decking
Hyperion Deck Board Dimensions
The following example will use a decking area of 3m wide and 6m long and 4m Explorer decking boards (145 x 21mm) with 6mm hidden fasteners:
RangeBoard LengthBoard WidthBoard Depth

Step 3

If the boards are laid legthways, to find the number of board rows, divide the deck width by the width of the board plus a 6mm spacing per board (allows for the hidden fastener gap)

Step 4

Multiply the length of the deck by the number of boards wide (given above). This gives you the total linear meters of deck boards required

Step 5

Finally divide the total linear meters of decking by the length of boards being used
3m width / (0.145m + 0.006m) = 20 boards wide
6m length x 20 boards wide = 120 linear meters
120 linear meters / 4m board length = 30 lengths of 4m decking boards

Picture Frame Border

If you plan to have a
picture frame border
, add on the length of the boards running against the overall board direction, then divide by the length of the decking board used
6 linear meters / 4m length decking board = 1.5 boards
Always round up to help you determine how many more decking boards and accessories will be required, so in this case 2 boards.