How many deck boards for a 10x10 deck?

You need 22 deck boards at 10 ft long.

That is 22 rows across the 10 ft span, or 220 linear feet. Buy 243 linear feet to cover the usual 10% for cuts and defects.

Where that number comes from

A standard 5/4x6 or 2x6 deck board is 5.5 in wide once milled, not 6 in. Add the 0.125 in drainage gap between boards and each row covers 5.625 in of deck.

  1. 10 ft across × 12 = 120 in to cover
  2. 120 ÷ 5.625 = 21.3 rows, rounded up to 22
  3. 22 rows × 10 ft long = 220 linear feet
  4. Add 10% for cuts and culls = 243 linear feet

Boards run the length of the deck here, so the 10 ft dimension sets board length and the 10 ft dimension sets how many rows you need. Running them the other way swaps the two numbers.

Change the numbers

What else the frame needs

  • Joists at 16 in on centre: about 8 for a 10 ft run.
  • Footings: roughly 9 for a deck this size, depending on beam layout and frost depth.
  • Deck screws: around 492 — two per board at every joist crossing.

Joist and footing counts vary with span tables, beam placement and local frost depth. Treat them as a shopping estimate, not a structural design, and check your local code before you build.

Getting it right

  • Measuring the frame, not the decking. Decking usually overhangs the rim joist by an inch or so on open sides. Measure the surface you intend to cover.
  • Buying nominal widths. A "6 inch" board is 5.5 in. Sizing off 6 in leaves you roughly 9% short — on this deck that is about 20 linear feet missing.
  • Skipping the gap. Boards need the 0.125 in gap to drain and to move with humidity. Butting them tight traps water and cups the boards.
  • Ordering exact. Ten percent covers bowed boards, knots and cut-offs. It is cheaper than a second delivery.

Other deck sizes

Deck calculator for any size, or all calculators.