Deck Board Layout Calculator

Plan how deck boards will land before fastening the first one

Deck boards rarely divide perfectly across the finished deck width. If you simply start with a full board, the last board may become an unattractive narrow rip. This calculator lets you compare a full-board start with a balanced layout that shares the cut between both edges.

Use the installed dimensions

Measure the total finished width perpendicular to the board direction. Enter the actual visible board face width and the installed gap you intend to maintain. MeasureMarks calculates each board start and, in balanced mode, adjusts the two edge boards equally.

Before fastening boards

• Use the actual board width; wood and composite decking can differ from nominal dimensions.
• Choose a gap based on the decking manufacturer’s requirements and expected installed condition.
• Check the calculated edge-board width before starting, especially around fascia, picture framing, or border boards.
• Re-check the deck width in several locations if the framing is not perfectly square.