Deck Boards Calculator
Fill in the values and the answer updates as you type.
How the Deck Boards Calculator works
Rows = deck width ÷ (board width + gap). Boards per row = deck length ÷ board length, rounded up. Add the waste allowance for cuts and defects. Example: with Deck length 16 ft, Deck width 12 ft, and Board width 5.5 in, the result is Boards to buy = 58; Rows of boards = 26; Deck area (sq ft) = 192.
Inputs and results
The Deck Boards Calculator takes 6 inputs and gives 3 results.
What you enter
- Deck length (ft) — starts at 16.
- Deck width (ft) — starts at 12.
- Board width (in) — starts at 5.5.
- Board length (ft) — starts at 12.
- Gap between boards (in) — starts at 0.125.
- Waste allowance (%) — starts at 10.
What you get
- Boards to buy
- Rows of boards
- Deck area (sq ft)
Example: Deck Boards Calculator with the starting values
With deck length 16 ft, deck width 12 ft, board width 5.5 in, board length 12 ft and gap between boards 0.125 in, the calculator returns:
| Boards to buy | 58 |
|---|---|
| Rows of boards | 26 |
| Deck area (sq ft) | 192 |
Change any value above and the results update straight away.
Deck Boards Calculator FAQ
How do I use the Deck Boards Calculator?
Enter deck length, deck width, board width and board length in the fields, then read boards to buy, rows of boards and deck area (sq ft) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Deck Boards Calculator calculate?
Deck boards needed for a rectangular deck. It returns boards to buy, rows of boards and deck area (sq ft) from the 6 values you provide.
What values does the Deck Boards Calculator start with?
It opens with deck length 16 ft, deck width 12 ft, board width 5.5 in and board length 12 ft so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Deck Boards Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Deck Boards Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.