Material calculator
Deck board calculator — boards & screws
Estimate decking board count, total decking linear feet, and exposed screw count from deck dimensions, board width/gap, joist spacing, and board length.
You'll need
29 boards
Deck boards
- Decking length
- 458 linear ft
- Exposed screws
- 744 screws
What this assumes
- Rows = ceil(12 ft × 12 ÷ (5.5 in + 0.1875 in)) = 26.
- 26 rows × 16 ft, +10% waste, ÷ 16 ft board length.
- Screws = 2 per board per joist crossing at 16 in o.c.; hidden fasteners use a different count.
Coverage rates & sources
Every number this calculator uses is a published engineering constant — not an estimate we made up. Here is exactly what it assumes and where each value comes from.
- 5/4×6 / 1×6 board actual width: 5.5 inSource: Nominal-to-actual (most popular residential deck board)
- Standard board gap: 3/16 in (0.1875)Source: Typical drainage/expansion gap for deck boards
- Joist spacing (standard): 16 in o.c.Source: Standard deck-board support spacing
- Screws per 100 ft² @ 16 in o.c.: ~350 screwsSource: Decks.com / industry (2 screws/board/joist)
- Screws per 100 ft² @ 12 in o.c.: ~467 screwsSource: Industry (tighter joist spacing)
- Perpendicular layout waste: 10%Source: Standard decking waste
- Diagonal layout waste: 15%Source: Standard for diagonal decking
Before you buy
- Covers the walking surface only, not joists, beams, posts, ledger, railing, fascia, or stairs.
- Board count depends on the board lengths sold locally and the cut plan; minimizing joints may change the order.
- Hidden-fastener systems are counted by clips, not exposed screws.
This is a planning estimate, not a substitute for a pro's on-site measurement. For load-bearing, structural, or code-regulated work, confirm quantities with a licensed contractor.
Related calculators
- Fence calculator — posts, panels & concreteEstimate fence posts, equal sections, panel or picket counts, and concrete from the run length and post-hole dimensions. Concrete uses annular volume: hole volume minus buried post volume.
- Deck joist calculator — joist countCount deck joists at a selected on-center spacing. This deliberately does not size joists; span, species, loads, and ledger attachment are structural/code questions.
- Stair & stringer calculator (IRC)Enter your total height (finished floor to finished floor, or ground to deck) and this lays out a code-compliant stair: number of risers, exact riser height, number of treads, total run, and stringer length. Riser and tread limits come from the International Residential Code.
- Wheelchair ramp slope calculator (ADA)Enter the height the ramp has to climb and this returns the minimum ramp length at the ADA's 1:12 maximum slope, plus how many runs and level landings the rise requires. Built from the 2010 ADA Standards.