Deck Cost Calculator
Planning to build a new deck? Enter your desired dimensions, select your decking material, height, and labor option to estimate total material and professional construction costs.
Results
Decking boards are less than half the cost
People price a deck by the board, and the board is the smaller half of the bill. Under the surface sit joists, beams, a ledger, posts and footings, and above it — on anything raised — railings and stairs. This calculator prices the whole stack, which is why its total is usually well above a boards-only estimate.
| Component | Basis |
|---|---|
| Decking boards | $10 to $45 per sq ft, by material |
| Framing, joists and ledger | $5.00 ground level, $6.50 elevated, $9.00 second story |
| Posts and concrete footings | $65 each, spaced up to 8 ft |
| Railings | $22 per linear foot, on three sides |
| Second-story stairs | $1,200 for a typical run |
Framing costs rise with height because the structure carries more: taller posts, deeper footings, larger beams and mandatory bracing. A second-story deck also needs stairs, and stairs are the most labor-intensive part of any deck.
Decking material is the decision that sets the budget
| Material | Cost per sq ft | Life | Upkeep |
|---|---|---|---|
| Pressure-treated pine | $10 | 10 to 15 yr | Clean and seal every 2 to 3 yr |
| Cedar or redwood | $18 | 15 to 20 yr | Seal annually to hold color |
| Composite | $28 | 25 to 30 yr | Wash only; no sealing |
| Ipe hardwood | $45 | 40 yr+ | Oil for color, or let it gray |
Composite costs two to three times pressure-treated up front and wins over a long enough horizon, since sealing a wood deck every few years is a real recurring cost in both money and weekends. It is not maintenance-free, though — it stains, it holds heat noticeably in direct sun, and cheap early-generation composite fades unevenly.
DIY, and the parts that are not a DIY job
Labor roughly doubles the cost of a deck: $25 per square foot for a standard builder, $35 for a premium one, against materials of $20 to $60 all-in. Building it yourself is the single largest saving available on the project.
Two details are worth paying for regardless. The ledger connection, where the deck attaches to the house, causes more deck collapses than any other component; it needs proper structural fasteners and flashing, and nails alone are not acceptable. Footing depth is the other: footings must reach below the frost line, which is 42 inches or more in northern states, or the deck heaves and racks every winter.
Permits are near-universal
Most jurisdictions require a permit for any deck over 30 inches above grade, and many require one for any attached deck at any height. Inspection typically happens twice, once with the footings open and once at completion, so the schedule has to allow for it.
This matters beyond code compliance. An unpermitted deck surfaces during a home sale, and the resolution is retroactive permitting, or removal, at the seller's expense. Treat the permit fee as part of the build cost rather than an optional extra.
Frequently asked questions
How much does a 12x12 deck cost to build?
A 12 × 12 ground-level deck is 144 sq ft. In pressure-treated wood that is about $1,440 in decking, $720 in framing and $390 in footings — about $2,550 in DIY materials. Professional installation at $25 per sq ft adds roughly $3,600 in labor, which is more than the materials cost.
Does composite decking cost more than wood?
Yes, composite decking (like Trex) costs roughly 2x to 3x more upfront than pressure-treated wood. However, composite decking requires virtually no annual maintenance, saving money on staining and sealing over its 25+ year lifespan.
How many support posts are needed for a deck?
Decks generally require support posts spaced no more than 8 feet apart. For a standard 16x12 deck attached to a house ledger, you typically need 6 support posts and concrete footings.
Do I need a permit to build a deck?
Usually. Most jurisdictions require a permit for any deck more than 30 inches above grade, and many require one for any attached deck at any height. Expect two inspections, one with the footings still open. An unpermitted deck also surfaces during a home sale, where the fix is retroactive permitting or removal, paid for by the seller.