Deck Building Cost Calculator

Deck costs by size, material and region — pressure-treated through composite, including footings, railing and stairs.

Your project

Finish level

Estimated total cost

$13,800 – $24,150

300 sq ft · Mid-range · National average

$46 – $81 per sq ft

Materials
$6,000 – $10,500
Labour
$5,280 – $9,240
Permits & fees
$720 – $1,260
Contingency (15%)
$1,800 – $3,150
Typical timeline
1–5 weeks of active work
Recouped at resaleAbout 65% of a mid-range spend
$12,334
  • National average pricing. Pick your region to adjust for local labour rates.
  • This is a planning range, not a quote. Get three itemised bids and compare the scope line by line — the cheapest bid is usually the one that left something out.

What the estimate includes

  • Footings and posts to frost depth
  • Framing, ledger and flashing
  • Decking, railing and stairs
  • Fasteners and hardware
  • Permit and inspection

What it does not include

  • Roof, pergola or screened enclosure
  • Electrical, lighting and outdoor kitchens
  • Grading, retaining walls or difficult site access
  • Repair to the house framing at the ledger

What actually moves the price

  • Material. Pressure-treated is roughly half the installed cost of composite, but composite saves the staining you would otherwise do every two or three years.
  • Height. A deck more than a few feet up needs taller posts, more bracing, railing all round and stairs — all of which scale faster than the deck surface does.
  • The ledger connection. It is the detail inspectors care about most and the failure that causes deck collapses. It is not the place to save money.

How these estimates are built

  • Base costs are typical 2025–2026 US pricing per square foot at each finish level, drawn from national remodelling cost surveys and contractor bid data.
  • Your region multiplies that base — coastal metros run 30–40% above the national average and rural markets 15–20% below, almost entirely on labour rates.
  • The contingency is added on top of the base range rather than taken out of it, because that is how the money actually behaves on a job site.
  • The materials, labour and permit split shows how the mid-point of the range typically divides. It is a way to read a bid, not a second estimate.
  • Resale recoup figures follow national cost-versus-value patterns. No renovation returns more than it costs — treat the figure as a partial rebate on something you are buying for yourself.

Frequently asked questions

How much does it cost to build a deck?

$20–$40 per square foot for pressure-treated and $40–$70 for composite, installed. A 300 sq ft deck is therefore roughly $6,000–$12,000 in pressure-treated and $12,000–$21,000 in composite before regional adjustment.

Is composite decking worth the extra cost?

Over about ten years, usually. Composite costs roughly double upfront but eliminates staining and sealing every two to three years, and does not split or splinter. Under five years of ownership, pressure-treated is the better financial call.

Do I need a permit to build a deck?

Almost always for anything attached to the house or above about 30 inches. The inspection is really about the ledger connection and the footings — the two things that fail catastrophically when they are wrong.

Before you commit the budget, see it finished

Upload a photo and generate photorealistic versions of the finished space in any style. It is far cheaper to change your mind here than after the cabinets arrive.

Visualise the finished space

Material calculators for this project

Deck CalculatorDeck boards, joists, footings and fasteners from your deck dimensions — plus what pressure-treated versus composite really costs.Concrete CalculatorCubic yards for a slab, footing or column — and the honest bag count, so you know when to stop bagging and call a truck.Paver Patio CalculatorPaver count plus the base gravel, bedding sand and edging that make up most of the real cost of a patio.

Related projects

Home AdditionRoom addition and bump-out costs per square foot — foundation, envelope and mechanical work included, because an addition is a small house.Roof ReplacementRoof replacement costs by roof area, material and region — including the tear-off and decking repair that turn up on the change order.Kitchen RemodelWhat a kitchen actually costs by size, finish level and region — with the cabinet, labour and permit split that the headline number hides.