ContractorHandbook

How Many Boards for a 16x24 Deck?

Deck boards to buy

51 16 ft boards

384 square feet, 816 linear feet of decking, joists 16 inches on center.

It does not stop at a number.

When the figures look right, the deck material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.

boardgap betweenboardsdeck width, ftwidth / (board + gap) = rows, rows x length = linear feet
Decking is bought in linear feet and laid in rows, and the gap between boards is what sets how many rows fit. A quarter inch gap across a twelve foot width is most of an extra board, which is the difference between one trip and two.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Deck length24 ft
  • Deck width16 ft
  • Board face width5.5 in
  • Gap between boards0.25 in
  • Board length you buy16 ft
  • Joist spacing on center16 in

Deck boards to buy51 16 ft boards

Deck area384 sq ft
Board rows across the width34
Linear feet of decking816 lf
Boards at 16 ft51
Joists at 16 in on center19

The material list this produces

Deck boards, 16 ft51
Joists, 16 ft19
Joist hangers, each38
Deck screws, lb12

Board length compared

Same deck, four board lengths. Longer boards mean fewer end joints and more offcut risk.

Board lengthDeck boards to buy
8 ft boards102 8 ft boards
12 ft boards68 12 ft boards
16 ft boards51 16 ft boards
20 ft boards41 20 ft boards

What else matters here

Three hundred and eighty four square feet is bigger than a lot of first apartments, and it is firmly in engineered territory. At this size the permit set usually wants a framing plan, footing sizes and a ledger detail, and the inspector will look at all three.

The ledger is where decks fail. Almost every catastrophic deck collapse traces to a ledger nailed rather than bolted, or lagged into siding rather than into the rim joist, or flashed badly enough that the rim rotted. Bolt it, flash it, and photograph it before the decking goes on.

Fifty one boards is around a ton and a half of pressure treated lumber arriving wet. Stack it flat with stickers between layers and let it dry a week before laying, or the gaps you set at a quarter inch will open to half an inch by August.

What this calculator assumes

  • A nominal 2x6 board is 5.5 inches of actual face. Nominal sizes are not real sizes, which is where most deck orders go wrong.
  • Joist count is the span across the deck width at the spacing given, plus one for the last joist.
  • Waste is not added. Add 5 to 10 percent if the deck is not a plain rectangle.

Questions people ask

How many deck boards for a 16x24 deck?

About 51 boards of 5/4 by 6 at 16 feet, covering 816 linear feet across 34 rows.

How should a deck ledger be attached?

Through bolts or approved structural screws into the house rim joist, with proper flashing above. Nails and lag screws into siding are the single most common cause of deck collapse.

Should I let pressure treated decking dry first?

Yes. It arrives saturated and shrinks as it dries, so boards laid tight while wet end up with wide gaps. A week stickered and flat makes a visible difference.

Different numbers?

The deck calculator takes any dimensions you like and hands back the same list.

Other common sizes