Deck materials calculator

Enter length, width, and height off the ground. Change every input. Prices start as labeled defaults; overwrite them with a current lumberyard quote. This is a materials count, not a contractor quote.

Size

Length (ft)Width (ft)Height off grade (in)Waste %Joist spacing (in)Board width (in)Board length (ft)

Materials and prices

Defaults are labeled edit-me in the data file. Overwrite them with a current yard quote.

DeckingDecking price ($ / lf)JoistsJoist price ($ / stick)PostsPost price ($ each)FastenersFastener price ($ each)Footing allowance ($ each)Railing allowance ($ / lf)Include railing allowance

Material ballpark

$4,978

320 sqft walking surface. Materials only, not labor or permit.

Decking lineal feet	768.1
Decking boards	65
Decking board-feet	352.0
Joists (count / lf)	16 / 312.0
Posts	8
Fasteners	3,169
Decking $	$3,456
Framing $	$592
Fasteners $	$570
Footings $	$360
Railing $	$0

Board and fastener prices are labeled defaultEnterable because 2026 retail lumber/composite prices move weekly and a citable Home Depot / published-average snapshot was not captured as a stable primary source. Users must overwrite defaults. Coverage, spacing, and waste factors are construction-practice defaults (IRC-style 16 in OC joists, 5/4×6 decking), not a price quote.
Joist lineal feet use the published recipe: 0.75 x deck sf plus perimeter. Confirm spans with a table.