Deck Board Calculator
Find how many deck boards a deck needs for your board width, length and gap, with the cost.
Change the values and press Calculate to work out your own figures.
Enter the deck's length and width and the board size.
Show the working
- boards = deck area ÷ ((board width + gap) × board length), rounded up
How to use it
Enter the deck's length and width and the board size.
Lengths can be decimals, fractions or tape entries such as 12' 6 1/2" (in feet or inches). Prices are optional.
Key facts
boards = deck area ÷ ((board width + gap) × board length), rounded up
Waste
Add about 10% for straight decking and 20% for diagonal or patterned layouts.
Questions
How many 16 ft deck boards for a 10 × 20 ft deck?
28 boards of 5.5 in, before waste.
Formulas
boards = deck area ÷ ((board width + gap) × board length), rounded up
Sources
Limitations
- Material densities are typical values (the midpoint of the commonly published range); real loads vary with moisture, grading and compaction, so check with your supplier or type in their density.
- Tank results are the geometric volume; real tanks have wall thickness and fittings.