Deck Cost Calculator
Estimate a deck by size, material, height, railing, and stairs. See materials, labor, permits, and the total before you call a builder.
How this deck estimate works
The calculator starts with a material and labor rate per square foot, then adjusts for deck height, railing, stairs, removal, and a permit allowance. The result is a planning range, not a contractor bid.
Deck area × material rate + deck area × labor rate + railing + stairs + removal + permit = estimated total. DIY removes the labor lines.
Deck cost by material
| Material | Material per sq ft | Installed per sq ft | 16 × 20 project |
|---|---|---|---|
| Pressure-treated wood | $15–$22 | $35–$47 | $11,200–$15,000 |
| Composite | $25–$40 | $43–$64 | $13,800–$20,500 |
| PVC | $30–$45 | $50–$71 | $16,000–$22,700 |
Surface and framing, excluding railing, stairs, and permits. Add $1,200–$2,400 for a 40 ft railing run.
Deck cost by size
| Size | Square feet | Pressure-treated | Composite |
|---|---|---|---|
| 10 × 12 | 120 | $4,200–$5,600 | $5,200–$7,700 |
| 12 × 16 | 192 | $6,700–$9,000 | $8,300–$12,300 |
| 16 × 20 | 320 | $11,200–$15,000 | $13,800–$20,500 |
| 20 × 24 | 480 | $16,800–$22,600 | $20,600–$30,700 |
Railing, stairs, and height
- Railing: $30–$60 per linear foot installed, depending on material and infill.
- Stairs: $500–$1,500 per set, more for wide or wrapped stairs.
- Height: a raised deck adds 15–30% for longer posts, bracing, and larger footings.
- Removal: $3–$6 per square foot to tear out and haul away an old deck.
- Permit: often $200–$500, plus inspection time.
DIY vs. professional
A simple ground-level deck is a realistic DIY project if you are comfortable with footings, framing, and levels. A raised or second-story deck is a different job: fall protection, ledger flashing, and engineered attachments matter. If the deck is attached to the house or requires an inspection, hire a licensed contractor.
Before you build
- Confirm the deck height, size, and setback rules with your city or HOA.
- Ask for a line-item bid: framing, decking, railing, stairs, footings, permit.
- Check the ledger attachment and flashing detail; this is where decks fail.
- Decide on composite vs. wood based on 10-year cost, not just the first quote.
- Budget for inspection corrections and a weather buffer.
Frequently asked questions
How much does a 16x20 deck cost?
A 320 sq ft deck typically costs $11,000 to $22,000 installed, depending on material, height, railing, stairs, and local labor. Pressure-treated wood is at the low end; composite and PVC are higher.
Is composite decking worth the extra cost?
Composite costs 40–70% more upfront than pressure-treated wood, but it needs less staining and maintenance. If you plan to stay in the house for 10+ years and dislike annual upkeep, the total cost can be closer than the first quote suggests.
Do I need a permit for a deck?
Most jurisdictions require a permit for an attached deck, a deck more than 30 inches above grade, or a deck with stairs and railings. Rules vary, so check with your local building department before buying materials.
How much does deck railing cost?
Railing typically adds $30–$60 per linear foot installed, depending on material and infill. A 40 ft railing run can add $1,200–$2,400 to the project.
Can I build a deck myself?
A simple ground-level deck is a realistic DIY project if you are comfortable with framing, footings, and levels. Raised decks, second-story decks, and complex stairs are better left to a licensed contractor, especially where inspections are required.
How long does a deck take to build?
A professional crew usually finishes a 320 sq ft deck in one to three weeks, depending on weather, inspections, and material lead times. A DIY build often takes several weekends.