Deck Material Calculator

Why this page exists

Boards, joists, posts, fasteners

A clean estimating template for the major line items you need to bid a deck.

Plug in the deck size

Pick 10×10 through 20×24 and back into board count, joist count, and railing run.

See the deck on the actual yard

A material list nobody can picture is just a spreadsheet. Render the deck so the homeowner sees what they’re buying.

Faster than spreadsheet quoting

Get a phone-first estimate and render in the time it used to take to find the tape measure.

How it works

1. Upload a backyard photo. Use any phone photo of the build site. No measurements, no CAD file.
2. Mark the deck area. Drag to outline where the deck goes. Add stairs or a railing line if you want them.
3. Choose material and design. Pick composite, PVC, cedar, or pressure-treated. Compare looks on the same photo.
4. Generate the render and share. Get a photorealistic render in seconds. Send it to the homeowner or attach it to a proposal.

Deck Material Calculator

Use this as a sanity-check estimating template, not a final cut list. Once the design is agreed, your framing software or contractor will tighten the counts.

Most deck failures are framing and footings, not decking. PaperPlan won’t generate engineering specs, so use a span table or your local code. The render handles the visual side; you handle the structure.

Fastener benchmark: Trex Hideaway Universal clip coverage. Check the fastener system and joist spacing for your chosen boards.

Cost assumptions and sources

U.S. planning allowances in USD for a simple, single-level deck, including ordinary materials and contractor labor. These are PaperPlan editorial assumptions, not surveyed averages or a local quote.

• Pressure-treated: $25 – $40 / sq ft installed (USD)
• Composite: $45 – $70 / sq ft installed (USD)
• PVC: $60 – $90 / sq ft installed (USD)

Multiply deck area (width × length in feet) by the selected installed rate, then round each end of the range to the nearest $100.

Demolition, permits and engineering, taxes, stairs, railing, roofs, unusual foundations and difficult site access need separate quotes. Location, product selection and labor can put a real bid outside these ranges. Canadian projects need local CAD pricing.

The manufacturer sources below explain scope and cost drivers; they do not validate PaperPlan’s exact installed-rate bands. Supplier material estimates should not be compared directly with an installed project budget.

• Trex: deck material cost calculator: Estimates materials and explicitly excludes labor; prices vary with location, season and design.
• TimberTech: understanding deck costs: Separates decking, railing, labor and substructure, and explains the impact of site and project features.

Sources and assumptions reviewed 2026-09-09. Confirm the scope and current price with local contractors before budgeting a build.

Common questions

How do I calculate decking board quantity?

Take the deck square footage and divide by the coverage of one linear foot of board. For a standard 5.5" board that’s 5.5 ÷ 12 = 0.4583 sq ft per linear foot. Divide area by that coverage, then add 10% waste before rounding up. A 12×16 deck needs 419 linear feet before waste, or 461 including waste. Diagonal layouts may need more; gaps are not deducted.

How many joists do I need for a 16x20 deck?

On 16-inch centers, a 16×20 deck needs about 16 joists (one every 16 inches across the 20 ft span, plus end joists). On 12-inch centers, it’s closer to 21.

Does this calculator size beams and footings?

No. Beam and footing sizing depends on local span tables, soil, and frost depth. Use a span table or pull a permit. The goal of this page is rough quoting, not engineering.

How does this connect to the render?

Pick the design, render the finished deck on the homeowner’s photo, then use the rough material list to back into a number. The render makes the homeowner say yes; the math defends the price.