DeckMath
Plan the whole deck · one project

Deck Project Planner

Enter your deck once and get everything: a shoppable lumber + hardware bill of materials, an itemized project cost with your state's labor rate, IRC 2021 compliance checks, a live 3D preview, and PDF / CSV export. Brand-neutral, mobile-first, no signup.

All materials & brandsShoppable BOM3D previewPDF & CSV exportIRC 2021Free · no signup
1 tool·Whole project
BOM·Shoppable list
50·States priced
PDF·Export + share
Quick answer

How do I plan a deck — materials and cost — in one place?

Enter your deck’s length, width, material, and pattern, then toggle railing, stairs, and lighting. The planner returns an exact lumber + hardware list (with store price-check links) and an itemized project cost — labor, permit, and a 10% contingency — adjusted for your state. Export a PDF or CSV, or share the link. No signup.
Output
BOM + cost + 3D
Materials
All brands
Cost
Free forever
Build your deck

Dimensions

Plan-view length × width.

ft

ft

Area · 192 sq ft·Perimeter · 56 ft
in

IRC R312 requires a 36″ guardrail above 30″.

192 square foot deck in Trex Enhance. 29 decking boards. Project total $18,629, $97 per square foot.
Project total · Northeast
$18,629
$97/ sq ft

192 sq ft · Trex Enhance · straight · 1.22× labor · incl. 10% contingency

Decking boards
16′ lengths
Joists
@ 16″ o.c.
Posts · footings
21 concrete bags
Lumber & hardware
shoppable BOM

Project advisories · IRC 2021

Joist span too long — 12′ > 10.4′ max

IRC R507.6

2×8 SPF joists at 16″ o.c. only span 10.4′. Reduce the width, add an intermediate beam, or step up to 2×10/2×12 joists. Run the Joist Span Calculator to size it.

Guardrail included (deck 36″ off grade)

IRC R312

IRC R312 mandates a 36″ guardrail on open edges above 30″. 40 lf of Composite system priced into the project.

Joist spacing set to 16″ o.c. for Trex Enhance

Manufacturer spec

Trex Enhance is rated for 16″ on-center under your straight pattern. The takeoff and board count already reflect this spacing.

Footings to 36″ frost depth (PA)

IRC R403.1.4

Pier footings must extend below the local frost line. PA minimum is 36″. Concrete quantity above assumes 12″⌀ piers — deepen as needed.

Hidden-fastener install premium applied

Manufacturer spec

Trex Enhance uses concealed clip systems — labor runs ~25% longer than face-screwing wood. That premium is baked into the labor line.

Lumber & hardware — shoppable list

Trex Enhance — 16′ decking boards
461 lf incl. 10% waste · straight pattern
29 boards · @ $61
$1,763
Joists — 2×8 PT
each 12′ long @ 16″ o.c.
13 joists · @ $28
$359
Beam lumber — 2×10 PT (built-up)
1× 2-ply built-up beam
32 lf · @ $3
$101
Posts — 6×6 PT
≤8′ o.c. on 1 beam line
4.0 posts · @ $52
$208
Post bases + beam caps (Simpson)
ABU66Z standoff base + PC6Z post-beam cap
4.0 sets · @ $41
$162
Footing concrete — 60-lb bags
9.4 cu ft · 4 piers, 36″ frost depth (PA)
21 bags · @ $3
$61
Joist hangers — Simpson LUS28
one per joist at the ledger / beam
13 hangers · @ $2
$25
Ledger attachment kit
13 lag bolts · 16 lf Z-flashing · 2× DTT2Z lateral anchors (IRC R507.9.2)
1.0 kit · @ $120
$120
Hidden-fastener clips
concealed clip system for grooved composite/PVC boards
192 sq ft · @ $1
$163
Materials subtotal
$2,963

Material-only quantities at 2026-Q1 national-average retail. Tap Home Depot / Lowe’s on any row to price it locally. Waste factored in (10% for the straight pattern).

Project cost summary

Lumber & hardware
Shoppable bill of materials above
$2,963
Railing — installed
40 lf · Composite system (Trex/TimberTech rail kit)
$3,120
Stairs — installed
5 risers · 4 treads · 36″ wide · concrete landing
$285
Labor — framing + decking install
Northeast · 1.22× index · Rectangle · hidden-fastener premium
$10,248
Building permit
Northeast typical fee (IRC R105)
$320
Contingency reserve (10%)
Industry-standard cushion for unforeseen scope
$1,694
Project total
Plan around this. Get 3 contractor bids — DeckMath should land within ±15%.
$18,629
Trex Enhance installs with hidden-fastener clips — labor is ~25% slower than face-screwing pressure-treated wood. That premium is already inside the labor line.

Lumber quantities use the same engine as DeckMath’s programmatic pages; pricing reflects 2026-Q1 national-average retail (Home Depot / Lowe’s) and RSMeans labor indices. Expect ±15% local variance. This plan is for budgeting and permit prep — not a substitute for a licensed inspector or structural engineer.

Footprint · top-down
16′ × 12′ · ≈ 192 sq ft
House side (ledger)16 ft12 ft
Footprint preview

Your rectangular deck

16′ × 12′ bounding footprint · ≈ 192 sq ft deck surface.

Visual preview · not engineered drawings

Save & share

Keep this deck — no account needed

Saved in this browser only. The whole project lives in the link — open it anywhere, or email it to a contractor.

Compare materials

Same deck, three materials side by side

Your 16′ × 12′ deck (192 sq ft), re-priced across brands. 25-year TCO adds maintenance to the build cost.

Materialcompositewoodcomposite
Project total
$18,629
$15,065
Lowest upfront
$19,488
Cost / sq ft
$97
$78
$102
Lumber & hardware
$2,963
$1,819
$3,705
Labor (install)
$10,248
$8,198
$10,248
Maintenance / yr
$10
$86
$10
25-yr total cost
$18,869
$17,225
Best long-term
$19,728

25-year total = build cost + 25 years of maintenance (stain/seal for wood; rinse-only for composite/PVC). Wood is usually cheapest upfront; composite/PVC often win on lifetime cost. Brand-neutral — no product is favored. Change the deck above and these scenarios re-price instantly.

Keep it looking new

Seasonal maintenance — Trex Enhance

No sanding, staining, or sealing — ever. Rinse 2× a year and spot-clean spills.

Est. upkeep / year
$10
192 sq ft · PA

Spring

  • Wash the deck (soap + water; composite: follow the brand's cleaner).
  • Inspect ledger flashing, fasteners, and railing posts for winter movement.
  • Check board clips are seated.

Summer

  • Keep the gaps between boards clear so they drain and ventilate.
  • Spot-check for loose boards before heavy entertaining season.
  • Rinse off pollen and grease; no sealing needed.

Fall

  • Clear leaves and debris from board gaps and corners (they trap moisture).
  • Deep-clean before winter; check that water still drains off.
  • Trim back vegetation touching the deck.

Winter

  • Sweep off wet leaves and standing water.
  • Avoid metal shovels and harsh ice-melt that can mar the surface.
  • Otherwise minimal — milder winters are easy on decks.

Upkeep cost is an estimate ($0/sqft/yr for Trex Enhance × 192 sq ft). Wood needs periodic stain/seal; composite & PVC are rinse-only. Always follow your manufacturer’s care guide.

How to use

How to use the Deck Project Planner in 5 steps.

  1. 01

    Enter your dimensions

    Set the deck length and width. Area and perimeter update instantly, and the 3D preview resizes to match.

  2. 02

    Pick a board + pattern

    Choose any decking material — pressure-treated, cedar, Ipe, or composite/PVC from every major brand — and a layout pattern. Joist spacing auto-sets to the board's code-rated maximum.

  3. 03

    Add railing, stairs, lighting

    Toggle the systems your project includes. Railing auto-flags as required above 30″ per IRC R312; stairs derive their step count from the deck height.

  4. 04

    Review the shoppable BOM + cost

    Get an exact lumber-and-hardware list with Home Depot / Lowe's price-check links, plus an itemized project cost with regional labor, permit, and 10% contingency.

  5. 05

    Export or share

    Download a PDF plan or CSV bill of materials, print it for the lumber yard, or copy a link that restores the whole project — no signup, ever.

How we calculate

How DeckMath calculates the result — IRC 2021 sources.

The planner runs one project state through DeckMath's shared takeoff engine, then prices every line at 2026-Q1 national-average retail. Lumber and hardware are material-only quantities (board count, joists, beams, posts, footings, fasteners); railing, stairs, lighting, and skirting are installed estimates; labor scales with area, your state's RSMeans index, the material category, and the footprint complexity.

IRC references

  • R507.6 — joist spans
  • R507.5 — beam spans
  • R507.3 / R403.1.4 — footings & frost depth
  • R312 — guardrails
  • R311.7 — stairs
  • R507.9.2 — lateral load anchors

Quantities use the same engine as DeckMath's programmatic pages. Pricing reflects 2026-Q1 national-average retail (Home Depot / Lowe's) and RSMeans regional labor indices. Plan for ±15% local variance and always get 3 contractor bids.

Decking boards
boards = ⌈(area ÷ board-face-width × waste) ÷ board-length⌉

Waste rises with the pattern (10% straight → 32% herringbone). Board face width and stock length come from the selected material.

Joists
joists = ⌈length × 12 ÷ spacing⌉ + 1

On-center spacing is auto-set to the material's prescribed maximum (tighter for angled patterns), so the board count stays code-compliant.

Posts + footings
posts = beam-lines × (⌈length ÷ 8⌉ + 1)

Footing concrete assumes 12″⌀ piers; deepen to your state's frost line. Lateral anchors (DTT2Z) are included on ledger-attached decks per IRC R507.9.2.

Project cost
total = (lumber + railing + stairs + lighting + skirting + labor + permit) × 1.10

Lumber is priced material-only at retail; railing/stairs/lighting are installed estimates; labor scales with area, region, material category, and footprint complexity. The 10% is a contingency reserve.

People also ask

Deck planner questions, answered.