How this calculator works
Estimate decking board count by effective board coverage, then add a waste allowance for trimming and defects.
Rows = deck width ÷ (board width + gap). Total linear feet = rows × deck length × (1 + waste). Boards = linear feet ÷ stock length.
Example
A 16 × 12 ft deck with 5.5 in boards typically needs two dozen or more full-length boards depending on orientation.
How to get a better estimate
- Board orientation changes the required stock lengths.
- Staggered joints can increase offcuts.
- Structural framing is not included in this board-surface estimate.
What the result means
The result is a planning estimate. Dimensions, coverage, density, packaging and installation conditions vary by product and project. For purchasing, compare the result with the exact product label or supplier specification. For structural, electrical, code-regulated or safety-critical work, use an appropriately qualified professional.
Common questions about the Deck Board Calculator
What does this calculator estimate?
Estimate decking board count by effective board coverage, then add a waste allowance for trimming and defects.
What formula does it use?
Rows = deck width ÷ (board width + gap). Total linear feet = rows × deck length × (1 + waste). Boards = linear feet ÷ stock length.
How should I use the result?
Use it as a planning estimate, then verify the dimensions and replace editable defaults with the specifications for the product or service you actually intend to buy.