ContractorHandbook

How Many Boards for a 12x24 Deck?

Deck boards to buy

52 12 ft boards

288 square feet, 26 rows running the 24 foot way, 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 width12 ft
  • Board face width5.5 in
  • Gap between boards0.25 in
  • Board length you buy12 ft
  • Joist spacing on center16 in

Deck boards to buy52 12 ft boards

Deck area288 sq ft
Board rows across the width26
Linear feet of decking624 lf
Boards at 12 ft52
Joists at 16 in on center19

The material list this produces

Deck boards, 12 ft52
Joists, 12 ft19
Joist hangers, each38
Deck screws, lb9

Board length compared

Same deck, four board lengths.

Board lengthDeck boards to buy
8 ft boards78 8 ft boards
12 ft boards52 12 ft boards
16 ft boards39 16 ft boards
20 ft boards32 20 ft boards

What else matters here

Twenty six rows at 24 feet is 624 linear feet, and in 12 foot stock every row is two boards meeting in the middle. Fifty two boards.

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 boards for a 12x24 deck?

Fifty two boards of 5/4 by 6 at 12 feet, two per row across 26 rows.

Different numbers?

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

Other common sizes