Decking Calculator: Determine The Number Of Decking Boards

To determine the number of decking boards multiply deck length and width for total square footage. Calculate each decking board’s square footage by multiplying its length and width. Divide deck square footage by individual board square footage for an estimate.

Decking Calculator

Enter the size of your deck and the size of decking boards to calculate the number of decking boards needed:








Deck Boards Needed = Deck Square Footage ÷ Individual Board Square Footage

deck calculator

Here’s the example based on the average deck size of 19’x19′ (approximately 361 square feet):

Imagine you have a deck with the average size of 19 feet by 19 feet, totaling around 361 square feet.

Your deck boards, measuring 12 feet by 5.5 inches (converted to 0.459 feet), have a square footage of 5.51 per board.

To estimate the number of boards needed, divide the total deck square footage by individual board square footage: 361 ÷ 5.51 ≈ 65.62 boards.

Take in consideration approximately 350 fasteners per 100 square feet of decking. For a 361-square-foot deck, anticipate using around 1263 fasteners.

Waste Factor (10%):

  • Adjusted Number of Boards = Number of Boards * 1.1
  • Adjusted Number of Boards = 65.62 * 1.1 ≈ 72.18 boards.

Waste Factor (20%):

  • Adjusted Number of Boards = Number of Boards * 1.2
  • Adjusted Number of Boards = 65.62 * 1.2 ≈ 78.74 boards.

Types of Deck Boards

There are three categories of deck boards: wood, composite, and PVC. If you opt for wood, you can choose between pressure-treated lumber, cedar, Ipe, mahogany, and tigerwood. You can purchase these in many sizes, but the most common is 5.5 inches wide and 12 or 16 feet long.

Composite and PVC decking comes in various styles and colors to mimic natural or painted wood. You can find composite and PVC decking in standard sizes that range from four to six inches wide and 12 to 20 feet long.

Types of Fasteners

Installing a deck requires the use of hundreds of fasteners. There are three main types: nails, screws, and hidden fasteners.

Frequently Asked Questions (FAQ)FAQ

What are plastic deck boards?

Plastic deck boards, also known as PVC deck boards, are made of 100% recycled plastic. They are a maintenance-free option but not the best choice for hot and sunny climates.

How are plastic and composite deck boards different?

Composite decking is a combination of plastic and wood fibers. Plastic deck boards contain plastic only.

How much spacing should you leave between deck boards?

You should leave a ⅛ inch to ¼ inch space between most deck boards. The type of boards, whether they’re dry, and what time of year you’re building factor into spacing decisions.