How many deck boards for a 16x16 deck?
You need 35 deck boards at 16 ft long.
That is 35 rows across the 16 ft span, or 560 linear feet. Buy 616 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.
- 16 ft across × 12 = 192 in to cover
- 192 ÷ 5.625 = 34.1 rows, rounded up to 35
- 35 rows × 16 ft long = 560 linear feet
- Add 10% for cuts and culls = 616 linear feet
Boards run the length of the deck here, so the 16 ft dimension sets board length and the 16 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 13 for a 16 ft run.
- Footings: roughly 9 for a deck this size, depending on beam layout and frost depth.
- Deck screws: around 1236 — 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 50 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.