How Much Decking Do I Need?
Deck board count comes from the area, the board width, and the pattern — with waste for cuts and a diagonal or picture-frame layout.
From area to boards
Take the deck area and divide by the coverage of one board (its face width × its length), accounting for the small gap between boards. A diagonal layout increases waste; a picture-frame border adds boards. The deck calculator counts them for your dimensions and pattern.
Don’t forget joists and hardware
Decking is only the surface — joists at 12–16 in on center, beams, hangers, screws and hidden fasteners all get counted separately. Skipping them under-orders the job.
FAQ
How do I calculate deck boards?
Divide the deck area by one board’s coverage (width × length), then add 10–15% waste, more for diagonal or picture-frame patterns.
How far apart are deck joists?
Commonly 16 inches on center, or 12 inches for composite or diagonal decking to prevent sag.