Deck Building Cost Calculator
Updated · Written and checked by Monu Kumar Modi · How we check our maths
Quick answer
Decks are priced by area and material. A 12 × 16 ft (192 sq ft) pressure-treated deck about 3 ft off the ground with railings and one set of stairs typically costs about $7,700–$9,500 built, including a permit. Composite decking costs roughly 50–80% more.
How this calculator works
Deck builders price the decking surface per square foot including the framing, footings and fasteners underneath, then add railings by the linear foot and each set of stairs as a unit. The material sets the base: pressure-treated pine is cheapest, cedar costs more, and composite and PVC cost most but need almost no maintenance.
Height matters because raised decks need longer posts, bracing and code-compliant railings, and second-storey decks need engineering and more labour at height. Most areas require a permit for decks attached to the house or more than about 30 inches off the ground.
Builders can set their own adjustment as a hidden setting and let homeowners design a deck on their website, receiving the size and material as a lead.
The formula
- Deck
- length × width × price per sq ft × height factor
- Railings
- railing ft × price per sq ft × 1.1
- Stairs
- sets × price per sq ft × 22
- Permit
- about $400 when included
Worked example
A 16 × 12 ft deck is 192 sq ft. Pressure-treated at $30 and raised 2–6 ft (×1.15) is $6,624. 28 ft of railing adds $924, one set of stairs $660 and the permit $400, for about $8,608, or $44.83 per sq ft.
Tips
- 01Composite costs more upfront but often less over 15 years once staining and repairs are counted.
- 02Check your property line and setback rules before choosing the size.
- 03Ask whether the quote includes footings, joist tape and hidden fasteners.
Frequently asked questions
How much does it cost to build a deck?
Most decks cost $25–$60 per sq ft installed, so a 12 × 16 ft deck is often $5,000–$12,000 depending on material and height.
Is composite decking worth it?
It costs more to build but needs no staining and lasts 25+ years, so many homeowners find it cheaper over the deck's life.
Do I need a permit for a deck?
Usually yes if the deck is attached to the house, higher than about 30 inches or larger than a set size. Check with your local building department.