Deck Board Calculator
Size your decking order. Enter the deck dimensions, board width, and gap to get the number of board rows, total linear feet to purchase including waste, and an estimated cost.
Your project
Estimate
Decking to buy · Includes waste allowance
- Board rows
- 35rows
- Estimated material cost
- $1,270.50
Estimates are guidance only and exclude tax, labor, and site conditions unless stated. Confirm with a local pro.
How it's calculated
No black boxes — here is the exact math behind your estimate, so you can check it or adapt it for your own quote.
- 1
Coverage per row (ft) = (board width + gap) ÷ 12 - 2
Rows = ⌈ deck length ÷ coverage per row ⌉ - 3
Linear feet = rows × deck width × (1 + waste% ÷ 100) - 4
Cost = linear feet × price per linear foot
Worked example
A 16 ft × 12 ft deck using 5.5" boards with a 1/8" gap and 10% waste.
Inputs
- Deck length
- 16 ft
- Deck width
- 12 ft
- Board width
- 5.5 in
- Gap between boards
- 0.125 in
- Waste allowance
- 10 %
- Price per linear foot
- 2.75 $/ft
Result
- Decking to buy
- 463 lin ft
- Board rows
- 35 rows
- Estimated material cost
- $1,270.50
Tools & materials for this project
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- Deck screws Corrosion-resistant screws for fastening decking.
- Hidden deck fasteners Give the deck surface a clean, screw-free look.
Compare local pros for a deck
An estimate gets you a budget. A few competing quotes get you the real price. Tell us about the job and we'll help you find vetted contractors nearby.
Deck Boards cost by state
The calculator does the quantity math exactly. What it can't know is what a fair unit price looks like where you live — a deck runs 61% more in the priciest US market than the cheapest.
Deck Boards cost in all 50 states + DC US average $35 per square foot installed · regional averages, full ranked table, and typical project totals.