How lumber quantity is estimated
Lumber quantity depends on the project type. For framing, the piece count is usually driven by stud or joist spacing across a span. For decking or sheathing, it is driven by coverage area divided by board face area. The calculator handles both approaches depending on the inputs.
Board feet are the standard volume measure for lumber purchasing. One board foot equals a piece 1 inch thick, 12 inches wide, and 12 inches long. The calculator converts the piece count and dimensions into total board feet so you can compare supplier pricing that is quoted per board foot.