When it comes to building a deck, however, there are many factors to consider, from the size of the seating area to the type of planks you intend to use. Before you embark on your bringing your deck ideas to life, you’ll need to understand the space and shape of the structure you are planning to build. You’ll also need to ask yourself one key question: how many deck boards will I need? We have the guidance, considerations and calculations you need here.

How many deck boards will I need? 

To calculate the deck boards, simply divide the width of the decked area by the width of the board and spacing to get the number of boards wide. Measure the length of the deck, then multiply the length x width (in feet and inches) to get the square footage. Don’t forget to calculate and add in extra if you are building deck stairs. You’ll also need to look at the board size and the spaces between the deck boards. If you do choose to lay your boards in a diagonal or herringbone pattern, be aware that you will require more materials. Wood decking can shrink, so the spacing should be no more than ⅛in if the wood has been treated with preservatives. Deck boards come in a variety of sizes, however, the most common size is the standard 6-inch width deck board. Once you have your total figure always add an extra 5-10% on for wastage; this will finally allow you to work out deck building costs, but you will also need to factor in the price for building a deck railing if this is part of the design. Always try to buy deck boards from the same batch to ensure they are a consistent color and finish.

How many deck boards do I need for a 12x12 deck?

According to Home Depot (opens in new tab), you need 29 12ft long deck boards for a 12x12 deck. However, we would always advise you do your calculations carefully yourself before buying.

How many deck boards do I need for a 10x10 deck?

You need 22 deck boards for a 10x10 deck. However, we would always advise you do your calculations carefully yourself before buying.

How do I calculate how much wood I need for a deck?

To calculate how much wood you need for a deck, first calculate number of boards to stretch across the width of the deck, then work out how many lengths you need. Multiply the totals.  If you are still hesitant, online tools, such as the deck board and materials calculator from Decks.com (opens in new tab) will help you confirm how many deck boards you will need. Also, be sure to consider the type of timber you intend to use. There are a variety of styles possible, from narrow matchstick planks to broad timbers, and options to buy new pressure-treated lumber or reclaimed hardwood. When you buy your materials, remember you’ll also need to purchase fixings, bolts and other hardware too.