Deck Board Calculator
Find out how many deck boards you need for your deck or patio, with waste included.
- Deck boards needed29 boards
- Linear feet of decking464 lin ft
- Deck area192 sq ft
- Area incl. waste211.2 sq ft
How to use
- Enter the deck length and width in feet.
- Enter the board width in inches (5.5" is common for 2×6 boards).
- Set a waste allowance and read the board count and linear feet.
About this calculator
This deck board calculator works out how many boards you need to cover a rectangular deck. It divides the deck area by the coverage of one board (length × width). Add a 10% waste allowance for end cuts, bad boards and future repairs — use 15% if your deck has angled corners or a picture-frame border. Results show board count and total linear feet, which is how lumber yards typically sell decking.
🧮 How it's calculated
- 1Step 1 — Board width in feet: Board width (ft) = Board width (in) ÷ 12
- 2Step 2 — Deck area: Area = Deck length × Deck width
- 3Step 3 — Add waste: Area with waste = Area × (1 + Waste% ÷ 100)
- 4Step 4 — Board count: Boards = ⌈Area with waste ÷ (Board width ft × Deck length)⌉
- 5Step 5 — Linear feet: Linear ft = Boards × Deck length
Boards = ceil( Deck area × (1 + Waste%) / (Board width ft × Board length ft) ).
Frequently asked questions
What width are most deck boards?+
2×6 lumber has an actual width of 5.5 inches; 5/4×6 decking is also 5.5 inches wide. Use 3.5 inches for 2×4 boards.
How much waste should I add for decking?+
10% is standard for a simple rectangular deck. Use 15% for decks with angled cuts, picture-frame borders or complex shapes.
Does this include the frame and joists?+
No, this calculates decking boards only. The structural frame (beams, joists, posts, hardware) requires a separate estimate.