Deck cost & materials calculator
A free deck building calculator: enter your deck size and material to get the boards, joists, footings, and fasteners you need, plus an installed cost estimate. Instant, no signup.
Short answer
Installed deck cost runs about $15–$25/sq ft for pressure-treated wood, $20–$38 cedar, $30–$60 composite, and $35–$70 PVC. A 12×16 (192 sq ft) composite deck is roughly $5,760–$11,520 and needs about 29 boards and 13 joists. Composite costs more upfront but needs no staining and lasts 25+ years.
Pressure-treated
$15–25/sqft
installed
Composite
$30–60/sqft
25+ yr
12×16 boards
~29
5½"×16ft
Joists
16" OC
standard
Deck board & material calculator
Board count includes a 10% waste allowance. Assumes 5½" boards.
Deck cost by material (installed, 2026)
| Material | Cost per sq ft | 12×16 deck (192 sq ft) | 16×20 deck (320 sq ft) |
|---|---|---|---|
| Pressure-treated wood | $15–$25 | $2,880–$4,800 | $4,800–$8,000 |
| Cedar / redwood | $20–$38 | $3,840–$7,296 | $6,400–$12,160 |
| Composite (Trex-style) | $30–$60 | $5,760–$11,520 | $9,600–$19,200 |
| PVC / vinyl | $35–$70 | $6,720–$13,440 | $11,200–$22,400 |
Installed cost (materials + labor), 2026 national ranges for a typical single-level deck. Site prep, stairs, railing upgrades, and permits can add to these figures.
Deck cost by material
Deck calculator vs. Home Depot & Lowe's
Retailer tools like the Home Depot, Lowe's, and Menards deck calculators price their own products. This calculator is brand-neutral: it returns the full bill of materials — boards, joists, footings, and fasteners — plus an installed cost range across pressure-treated, composite, and PVC, so you can compare before you buy.
How we calculate this
Every number on this page comes from the same formulas the calculator runs — a standard deck takeoff, not a lead-capture estimate. Here is the exact math:
- Deck area. length × width in feet. A 12×16 deck is 192 square feet.
- Deck boards. area ÷ the coverage of one board (board width in feet × board length), plus 10% cutting waste, rounded up. The default board is 5.5″ wide × 16 ft long, covering about 7.3 sq ft.
- Joists. deck length in inches ÷ joist spacing, plus one closing joist. The default spacing is 16″ on center; composite decking or diagonal patterns often call for 12″.
- Footings. two beam lines with posts every 8 ft along the length: 2 × (⌈length ÷ 8⌉ + 1).
- Fasteners. about 2.5 deck screws per square foot (two per board at each joist crossing).
- Installed cost. area × the material’s installed cost range per square foot (materials + labor).
Assumptions
- Rectangular, single-level deck; boards run parallel along the length.
- 10% waste factor on decking boards and linear footage.
- Posts 8 ft on center on two beam lines; soil and frost-depth conditions vary by region.
- Cost ranges are national mid-range figures — high-cost metros can exceed the top of the range.
Sources
Last reviewed: July 12, 2026
Related tools
Frequently asked questions
How much does it cost to build a deck?
Installed decks cost about $15–$25 per square foot for pressure-treated wood, $20–$38 for cedar, $30–$60 for composite, and $35–$70 for PVC. A 12×16 (192 sq ft) composite deck runs roughly $5,760–$11,520. Enter your size and material above for an estimate.
How many deck boards do I need?
Divide the deck area by the coverage of one board — a 5½-inch by 16-foot board covers about 7.3 square feet — then add about 10% for waste. A 12×16 deck (192 sq ft) needs roughly 29 boards. The calculator counts boards, joists, footings, and screws for you.
How far apart should deck joists be?
Most decks use joists 16 inches on center. Composite decking or diagonal board patterns often call for 12 inches on center for a stiffer feel. The calculator lets you pick 12, 16, or 24 inches and counts the joists accordingly.
Is composite decking cheaper than wood?
No — composite costs more upfront (about $30–$60 per square foot installed vs. $15–$25 for pressure-treated). But it needs no staining or sealing and lasts 25+ years, so over the life of the deck the total cost is often competitive.
Is this like the Home Depot or Lowe's deck calculator?
It does the same job — turning your deck size into boards, joists, and an installed cost — but it's brand-neutral and compares pressure-treated, composite, and PVC side by side instead of pricing one store's products.