Deck Board Calculator

The length of each board row (ft or m). Joists run across this dimension.
The dimension the board rows stack across (ft or m).
Uses the actual face width, not the nominal size: a "6 in" board is 5-1/2 in. Entering 6 gives 24 rows instead of 26 on a 12 ft width.
Used only for a Custom board, in inches (imperial) or millimetres (metric).
Used only for a Custom board.
Inches (imperial) or millimetres (metric). 0 is a tight-laid deck. TimberTech caps the side gap at 3/16 in.
The +15 % diagonal allowance is a design convention, not a manufacturer figure.
Applied to boards and fasteners after counting; rows and joists are never inflated. TimberTech recommends roughly 10 %. Manufacturer box-coverage claims already include overage, so do not apply it twice when buying by the box.
Boards to buy with waste
29
Decking Calculator
Board rows
26
Joists (including both end joists)
13
Boards to buy
26
Pieces per row
1
Stock length to buy
16 ft
Face screws
676
Face screws with waste
744
Hidden clips
338
Hidden clips with waste
372
Fasteners for the chosen method
676
Fasteners for the chosen method with waste
744
Deck area
192.00 sq ft
Deck area
17.837 sq m
Linear feet of board (whole rows)
416.00 ft
Linear feet by area / pitch (unrounded)
409.6 ft
Linear metres of board (whole rows)
126.80 m
Row pitch (board + gap)
5.6250
Side gap used
0.1250
Fasteners per square foot (chosen method, theoretical)
3.200
Worked out from American Wood Council, DCA 6 Prescriptive Residential Wood Deck Construction Guide, 2015 IRC version (two #8 screws per joist, about 1/8 in gap, 3-joist bearing, Table 2 joist spans) and 5 other sources.
Joist count includes the two end joists only; add doubled joists, blocking, ledger, beams and picture-frame borders separately. Joist size and span are not checked here (see AWC DCA 6 Table 2).
Joist size and span, beams, ledger attachment, posts and footings are set by the AWC DCA 6 guide and the building code adopted locally; this calculator counts decking boards, joists and fasteners only. Confirm quantities against a measure-up before ordering.

How this is worked out

8 steps
  1. Deck 16 x 12 ft = 192 x 144 in; area 192 sq ft (17.837 sq m)
  2. Row pitch = board 5.5 + gap 0.125 = 5.625 in
  3. Rows = ceil((W + g) / (b + g)) = ceil((144 + 0.125) / 5.625) = ceil(25.6222) = 26 (n boards cover n x b + (n - 1) x g, so the last partial row is a whole board)
  4. Joists = ceil(L / s) + 1 = ceil(192 / 16) + 1 = 13, counting both end joists
  5. Face screws = 26 rows x 13 joists x 2 = 676; with 10 % waste ceil(676 x 110 / 100) = 744
  6. Hidden clips = 26 x 13 = 338; with waste 372
  7. Row length 16 ft -> 1 piece(s) of 16 ft stock per row; boards = 26 x 1 = 26; with 10 % waste ceil(26 x 110 / 100) = 29
  8. Linear ft = 26 rows x 16 = 416 ft (area / pitch unrounded: 192 / 0.46875 = 409.6 ft)

Results are general information, not financial, tax, legal, medical or engineering advice.