How to use this calculator
- Enter Deck length in ft.
- Enter Deck width in ft.
- Enter Board width in in.
- Press Calculate. The highlighted row is your order quantity; the note beneath it translates the number into real-world terms.
Formula & constants
Board rows = deck width ÷ (board width + gap); each row is one deck-length board equivalent. A 5.5 in board with 1/4 in gap covers 5.75 in of width. Add 10% cut waste. Every default in the fields above is editable — when your supplier’s spec sheet lists a different density, coverage rate or price, enter that number instead. The waste and compaction allowances follow common trade practice; see our methodology page for the derivation of each formula and the standards it references.
Where this fits in the project
Framing quantities chain together: footings support posts, joists set the deck frame, and surface boards follow. Price hardwood and specialty stock in board feet, sheet goods by the sheet.
How this connects to your project
No quantity stands alone — each material in the chain depends on the ones around it. These are the planning steps that pair with the deck calculator:
- Lumber Calculator — Deck framing uses dimensional lumber.
- Joist Calculator — Deck joists support the deck boards.
- Board Foot Calculator — Premium decking priced per board foot.
- Deck Cost Calculator — Calculate material quantities before estimating cost.
- Stair Calculator — Decks often include stairs.
- Concrete Footing Calculator — Deck posts rest on concrete footings.
- Concrete Bag Calculator — Deck footings use bagged concrete.
- Fence Calculator — Decks and fences are common outdoor wood structures.
Frequently asked questions
How many linear feet of decking per sq ft?
About 2.1 lin ft of 5.5 in boards per sq ft of deck, before the 10% cut allowance.
What gap between deck boards?
1/4 in for drainage on dry lumber; green pressure-treated boards can be laid tight — they shrink to a gap.
Last verified: — prices reflect current national averages. See our methodology.
Estimates are for planning. Material densities, coverage rates and prices vary by region and supplier — confirm final quantities before ordering, and check local code where structural or electrical work is involved.