Follow these steps to calculate your decking material needs:

1. Enter Deck Dimensions: Measure the length and width of your deck in feet.
2. Provide Board Information: Enter the actual width of one deck board in inches (e.g., a "5/4x6" board is 5.5" wide) and the desired gap size between boards (e.g., 1/8" or 0.125").
3. Choose Board Orientation: Select whether your boards will run parallel to the deck's length or its width. This affects the calculation.
4. Set a Waste Factor: Add a waste factor (10-15% is standard) to account for cuts, angles, and defects. For diagonal patterns, use a higher factor (15-20%).
5. Calculate: The tool will compute the total linear feet of decking required and show how many boards of common lengths you need to buy.

• Decking: The surface material of a deck, typically made of wood or composite lumber.
• Linear Feet: A measurement of length, used for purchasing lumber.
• Board Orientation: The direction the deck boards run in relation to the house or deck frame.
• Joist: The parallel framing members that support the decking. Deck boards are installed perpendicular to the joists.
• Waste Factor: Extra material needed to account for cuts, mistakes, and unusable sections of boards.

"Your deck boards must run perpendicular to your joists. Before you decide on an orientation, confirm the direction of your joist layout. If you want a specific board pattern, like diagonal or herringbone, you may need to add extra blocking between the joists for support." - Experienced Deck Builder

"When buying boards, it's often smarter to buy longer lengths than you need and cut them down. For example, to cover a 12-foot wide deck, buying 12-foot boards is ideal as it eliminates seams. If you have to make a seam, always ensure it lands on the center of a joist."

• Forgetting the Gap: A small gap between boards is essential for water drainage. Forgetting to include it in the calculation will cause you to buy too much material.
• Using Nominal Width: Always use the actual, measured width of your decking (a "6-inch" board is usually 5.5 inches wide).
• Underestimating Waste for Complex Designs: Diagonal, herringbone, or multi-level decks require significantly more cuts and thus a higher waste factor (15-25%).
• Not Planning for Seams: If your deck's dimension is longer than the boards you can buy, you'll have 'butt joints' where two boards meet. These must land on a joist, which can affect your material usage.