How Much Does a Composite Deck Cost? | Honest Price Check

A composite deck typically costs $35–$70 per square foot installed, with most US projects landing between $7,500 and $21,000.

If you’re pricing out a composite deck, you’ve probably noticed the estimates swing wildly depending on where you look. That’s because “per square foot” figures mix two very different numbers: what you pay for the boards alone, and what you pay for a finished deck with framing, railings, and labor. The real question—what your project will actually cost—depends on scope as much as size.

What’s Driving the Price Range

Deck size matters, but it’s not the whole story. The same 300-square-foot deck can cost $7,500 or $21,000 depending on the choices below. Before you compare quotes, know which of these you’re paying for:

• Framing or substructure: Building on an existing frame is far cheaper than a new wood frame. A steel framing system like Trex Elevations® costs more still.
• Decking material tier: Entry-level boards run less than premium lines; capped polymer products cost the most.
• Railings: A basic top rail is one price; a full railing system with composite balusters is another.
• Stairs, site access, and old-deck removal: Each adds real money that square-foot math often hides.

Board prices run roughly $3–$9 per linear foot or $5–$18 per square foot for materials alone, depending on the line and brand. Labor typically adds $9–$15 per square foot when quoted separately. That’s why installed estimates cluster higher, around $25–$50 per square foot in some guides and $40–$80 per square foot including substructure in others.

Composite vs. the Premium Neighbors

Part of the confusion is category blur. “Composite decking” articles often include PVC and capped polymer products, which are a different material entirely. A recent 2026 dealer-survey estimate puts typical composite installed costs at $35–$70 per square foot, while luxury PVC and capped polymer projects can run $85–$125+ per square foot.

That distinction matters when you’re comparing. Check the material type before you treat any two numbers as comparable.

Table: Composite Deck Cost at a Glance

The last figure worth knowing is resale value. The 2025 Zonda Cost vs Value Report pegs a 16-by-20-foot composite deck addition at roughly $25,096, with about 88.5% of that recouped at resale. That makes composite one of the better-returning outdoor upgrades you can build.

Pricing Your Specific Deck

For a materials estimate on an actual footprint, Trex’s online cost calculator handles deck sizes up to 1,500 square feet. The workflow is simple: pick your deck size, choose the substructure (existing frame, new wood, or Trex Elevations® steel), then select a decking collection—Trex Select®, Enhance®, or Transcend®—and a railing style. It returns an estimate and can email an itemized breakdown for substructure, decking, and railing.

The calculator covers materials only; Trex is explicit that labor should be calculated separately. For a complete picture, you’ll want to pair its number with a local labor quote. If you’re working to a tighter budget, comparing entry-level lines before you commit can shave thousands—see our roundup of budget composite decking options that hold up for tested picks that don’t blow the budget.

One honest caveat: every estimate here assumes a straightforward build. Sloped yards, second-story installs, and complex stair runs all push costs upward. Get at least three itemized local quotes before you commit—per-square-foot averages get you in the ballpark, but your yard sets the final price.