Deck Board Calculator
How many deck boards to buy, from the deck size, board width, gap and board length.
Works in your browser. Nothing you type is sent to us.
The deck
Boards usually run parallel to the house, across the joists. Fractions like 12 1/2 work.
Decking boards
Frame
Prices optional
| Item | Quantity | Note |
|---|
Counts cover the deck surface and the joists under it. Beams, posts, footings, ledger, stairs and railings depend on the design and your code; add them from the drawings. Worked out in your browser, nothing you type is sent to us.
Deck Board Calculator at a glance
- Price
- Free
- Data sent to us
- None, it runs in your browser
- Sign-up
- Not needed
- Counts
- Boards, joists, rim joists, screws or clips, fascia
- Units
- ft and in with fractions, or m and mm
- Not counted
- Beams, posts, footings, stairs, railings
How to use Deck Board Calculator
- Type the deck sizeLength is the way the boards run, width is the way the joists run. Fractions like 12 1/2 work.
- Choose the boards and framePick the board, the gap, the board length you will buy and the joist spacing, and tick fascia or diagonal if they apply.
- Read the listThe boards, joists, fixings and fascia update as you type. Add prices to see the cost of what you priced.
Type the deck's length and width, choose the board width and gap and the length you will buy, and read how many boards to order with an allowance for cuts, plus the linear feet laid. Boards are counted by rows and whole lengths, the way a lumber yard sells them, not by dividing one area by another, so the number is one you can actually order. The joists, fixings and fascia are listed underneath if you need them too.
How it works
Deck Board Calculator is a web page that does its work on your own device. Everything you type or choose is worked out by your browser and never sent to a server, so nothing is stored and there is nothing to delete. There is no account, no sign-up and no limit on how often you use it.
Choosing the board length
Buy the length that divides your deck's length with the least left over: a 16 ft deck takes 16 ft boards with no joint, while a 14 ft deck wastes 2 ft of every 16 ft board but could use 12 ft boards with a 2 ft piece from a second board. Try each length in the calculator and compare the count.
Questions
Should I stagger joints in deck boards?
Yes, when a row needs more than one board, alternate where the joints fall and land every joint on a joist with a screw each side. Staggering does not change how many boards you buy, since each row is still cut from whole boards.
Other shortcuts
Deck Material Calculator · Decking Calculator
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