How Many Deck Boards for a 10x10 Deck?

A 10 × 10 ft deck (100 ft²) needs about 21 deck boards of 12 ft (or 16 of 16 ft) with 10% waste, using 5½ in boards with 1/8 in gaps. Underneath it needs 9 joists at 16 in spacing.

Your project

Usually the side along the house.

The direction joists run.

%

Covers cuts, bad boards and angled ends. Use 15% for diagonal decking.

Results

Deck boards to buy
21 boards
At your chosen board length, with waste
Rows of decking across the width
22 rows
Total decking length (with waste)
242 linear ft
Deck area
100 ft²

Framing underneath

JoistsEach as long as the deck width
9 joists

Fasteners

Screws (2 per board at each joist)
396 screws
  • If your boards are shorter than the deck length, plan for butt joints to land on a joist (use a double joist there), and add boards for the extra cuts.

Boards for a 10 × 10 ft deck, by board length

A 10 × 10 ft deck is the classic starter deck: a table with four chairs, or a couple of loungers. With 5½ in boards and 1/8 in gaps the deck has 22 rows, which is 220 ft of decking before waste. These counts include 10% waste:

Board lengthBoards to buyTotal length bought
8 ft boards31248 ft
10 ft boards25250 ft
12 ft boards21252 ft
16 ft boards16256 ft
20 ft boards13260 ft

Waste and layout

LayoutWaste12 ft boards16 ft boards
Straight, careful installer5%2015
Straight (typical)10%2116
Diagonal or picture-frame border15%2216

Joists and screws

Joists run the 10 ft width and are spaced along the 10 ft length.

Joist spacingJoistsScrews
12 in on center11484
16 in on center9396
24 in on center6264

That is just the decking surface, for a 100 ft² deck. Posts, beams, footings, ledger, railings and stairs are extra, and a permit is usually required.

Want to change anything else? The calculator above is the full Deck Board Calculator: edit any number and the results update instantly.

Tools & materials for this project

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Frequently asked questions

How many deck boards for a 10x10 deck?

With 5½ in boards, 1/8 in gaps and 10% waste, you need 21 boards of 12 ft, or 16 boards of 16 ft. That is 22 rows of decking across the 10 ft width.

How many joists does a 10x10 deck need?

At 16 in on center, 9 joists running the 10 ft width. At 12 in it is 11, and at 24 in 6. Joist size and span must follow your local building code.

How many screws for a 10x10 deck?

About 396 screws: two at every joist for each board. Buy a few extra, since they strip and get dropped.

Related sizes and guides

Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.