Enter your deck dimensions and board size to find how many deck boards you need and total linear feet of lumber.
Estimates only.
Each board covers a strip equal to its width (converted to feet) times its length. Divide total deck area by coverage per board, then multiply by the waste factor and round up. Multiply board count by board length to get total linear feet for your lumber order.
A 16 x 12 foot deck is 192 square feet. Using standard 5/4 x 6 decking (5.5 inches wide, 16 feet long) with 10% waste, you need about 27 boards. The calculator above gives you the exact count for your board dimensions.
Multiply the number of boards by the board length. For example, 27 boards at 16 feet each equals 432 linear feet. This is what you order at the lumber yard.
Most contractors leave a 1/8 to 1/4 inch gap between boards for drainage and expansion. This slightly reduces coverage per board, so add an extra 2 to 3 percent on top of your normal waste factor.
Pressure-treated lumber decks typically run $15 to $35 per square foot installed. Composite decking runs $30 to $60 per square foot. Material costs alone are roughly $5 to $15 per square foot depending on species and grade.