Deck Material Calculator
Build a full deck materials list — decking, joists, ledger, beams, posts, concrete footings, hardware, railing, and labor — with an itemized bill of materials, U.S. pricing, a cost-by-category chart, and a downloadable PDF.
Quantities use typical residential framing rules and may differ from an engineered plan. Prices use 2024-2025 U.S. figures and vary by region and grade. Confirm spans, footings, and codes with a local pro — for planning purposes only.
| Item | Qty | Unit | Unit $ | Total |
|---|
Estimated quantities for a attached deck at typical U.S. prices. Confirm spans and footing sizes locally.
How to use the deck material calculator
Four quick steps turn a deck’s dimensions into a full bill of materials — decking, framing, posts, footings, hardware, and railing — itemized, priced in U.S. dollars, charted by category, and ready to download as a PDF.
Enter your deck
Type length × width, deck height, and whether it’s attached to the house or freestanding.
Pick the decking
Choose material, board length, width and gap, and a pattern that sets the waste.
Set framing & footings
Joist size and spacing, beam span and plies, post spacing, and concrete per footing.
Read it & save a PDF
Get an itemized bill of materials, a cost-by-category chart, and a download.
How the material list is calculated
Decking runs the deck length across the joists; joists span the width; beams and posts carry the joists. Each part is counted from the deck geometry, then priced. Here is the exact math.
Worked example — 16 × 12 ft attached deck, 2×8 joists @ 16 in, 8 ft beam span, 2-ply beam, posts @ 6 ft
Decking: 26 rows × 16 ft = 416 lf × 1.05 ≈ 437 lf → 28 boards
Joists: ⌈(16×12) ÷ 16⌉ + 1 = 13 joists × 12 ft = 156 lf
Support lines: ⌈12 ÷ 8⌉ = 2 → beams = max(1, 2−1) = 1
Beam: 1 × 16 ft × 2 ply = 32 lf
Posts: ⌈16 ÷ 6⌉ + 1 = 4 → 4 posts, 4 footings, 8 bags
Railing: 2 × 12 + 16 = 40 lf
28 boards, 13 joists, 1 beam, 4 posts — roughly $2,450 in materials, about $12.75 / sq ft.
Framing, posts, and railing stay the same; only the decking line moves. Swapping pressure-treated for ipe on the same frame nearly doubles the surface material and lifts the whole job by roughly $1,700.
Deck framing, footing & cost charts
Handy lookups for the questions people ask most — the parts of a deck, joist counts, footings, materials, and typical U.S. costs. All quantities start from the deck’s length, width, and whether it’s attached.
| Part | What it does | Rule of thumb |
|---|---|---|
| Decking | The walking surface | Rows × length + waste |
| Joists | Carry the decking | Length ÷ spacing, + 1 |
| Ledger | Bolts an attached deck to the house | 1 × deck length |
| Beams | Carry the joists | 1–2 lines across the width |
| Posts & footings | Carry the beams to the ground | ~6–8 ft apart, 1 footing each |
| Railing | Guards the open sides | Open perimeter, in linear ft |
This calculator sizes each part from your deck dimensions. Actual spans and footing sizes must come from local code.
| Deck length | 12 in OC | 16 in OC | 24 in OC |
|---|---|---|---|
| 10 ft | 11 | 9 | 6 |
| 12 ft | 13 | 10 | 7 |
| 16 ft | 17 | 13 | 9 |
| 20 ft | 21 | 16 | 11 |
Joists = deck length in inches divided by spacing, plus one closing joist. Tighter spacing (composite, diagonal) adds joists; each spans the deck width.
| Nominal size | ~$ / lf | Typical use |
|---|---|---|
| 2×6 | $1.10 | Short spans, ground-level decks |
| 2×8 | $1.50 | Common mid-size deck joist |
| 2×10 | $2.10 | Longer spans, beams |
| 2×12 | $2.75 | Long spans, built-up beams |
Deeper joists span farther between supports. The right size comes from a span table for your species, spacing, and load — not from the price.
| Material | ~$ / lf | Upkeep | Best for |
|---|---|---|---|
| Pressure-treated pine | $2.00 | Seal periodically | Budget builds |
| Cedar | $2.75 | Seal periodically | Warm look, light weight |
| Composite | $3.75 | Low | Low-maintenance living space |
| PVC / vinyl | $4.50 | Very low | Wet climates, pools |
| Tropical hardwood (ipe) | $6.00 | Oil to keep color | Premium, long-life decks |
Decking price per linear foot — the surface line is usually the biggest single swing in the whole material list.
| Component | Typical cost | Notes |
|---|---|---|
| Framing lumber | $1.10–$2.75 / lf | By joist size |
| Support post | $10–$25 each | 4×4 or 6×6 |
| Concrete (bag) | $5–$8 each | ~2 bags per footing |
| Joist hanger | $2–$4 each | Galvanized / stainless |
| Railing system | $20–$60 / lf | Wood to metal / composite |
| Full deck, materials | $10–$25 / sq ft | Excludes labor |
| Full deck, installed | $30–$60 / sq ft | Materials + labor |
Planning ranges only. Prices swing with region, grade, and quantity, and railing can be a surprisingly large share of a small deck.
A deck is layers of load path: decking rests on joists, joists rest on beams, and beams carry down through posts to concrete footings. The calculator counts each layer.
- Decking — the surface, run across the joists in rows.
- Joists & ledger — joists carry the deck; an attached deck hangs them off a ledger.
- Beams — carry the joists across the width; span sets how many lines you need.
- Posts & footings — carry the beams to the ground, one footing per post.
Everything the calculator works out
One deck, entered any way you like, comes back as a complete bill of materials — every part counted, priced, and totaled.
Key figures behind a deck material list
Built for anyone pricing a deck build
From a ground-level platform to a raised attached deck, the same calculator turns dimensions into a full materials list and a per-square-foot cost.
Building a backyard deck and needs a shopping list of every board, post, and bag of concrete.
- Enter the deck, get a BOM
- Attached or freestanding
- Take the PDF to the yard
Turning deck dimensions into a priced material list and a per-square-foot number fast when quoting.
- Enter total area for odd shapes
- Compare decking materials
- Add install labor per sq ft
Weighing decking, railing, and labor before committing to a build or a bid.
- See cost by category
- Split materials from labor
- Save the PDF to shop quotes
7 tips for estimating deck materials
Small habits keep your material list right and your build to code, whether you’re planning a small platform or a raised wraparound.
Deck material calculator FAQ
The framing, footing, cost, and code questions people ask most.
A deck surface and frame need decking boards, joists, a ledger or rim board, beams, posts, and concrete footings, plus hardware like joist hangers and post bases, and usually railing. Fasteners and optional labor round out the list.
For a 16 by 12 foot attached deck that’s roughly 28 deck boards, 13 joists, a beam, 4 posts on 4 footings, joist hangers, post bases, and about 40 linear feet of railing. This calculator itemizes each into a full bill of materials.
Joist count is the deck length divided by the joist spacing, plus one for the closing joist. At 16 inches on center a 16 foot long deck needs about 13 joists, each spanning the deck width.
Composite and diagonal decking usually call for tighter 12 inch spacing, which adds joists. Always size joists and spacing against your local span tables and the decking maker’s rating.
Posts follow the beams. Count the support lines across the deck width, place a post about every 6 to 8 feet along each beam, and add one at each end — then put a footing under every post.
A small attached deck often needs a single beam on 3 or 4 posts and footings; a freestanding deck needs beams and posts on both sides. Footing size and depth follow your local frost line and code.
An attached deck bolts to the house through a ledger board, so one side is carried by the house and the joists hang from the ledger on hangers. A freestanding deck stands on its own beams and posts on every side.
Freestanding decks need extra beams, posts, and footings but skip the ledger and its flashing. The choice changes the framing count, which is why this calculator asks.
Deck materials commonly run from about $10 to $25 per square foot depending on the decking you choose — pressure-treated is cheapest, composite and hardwood cost more, and railing adds a lot per foot.
Adding professional labor brings a full built deck to roughly $30 to $60 per square foot installed. This calculator estimates materials, and lets you add a per-square-foot labor rate on top.
Beam size and post spacing come from the load and the span. The joists can only span so far between supports, which sets how many beam lines you need across the width; the beam then spans between posts, which sets how far apart the posts sit.
Bigger beams and closer posts carry more. Never eyeball this on a raised deck — use the span tables in your local code or have a pro size the beam, posts, and footings.
Railing runs along every open side. On an attached deck that’s usually the two ends plus the outer edge — about two widths plus one length; a freestanding deck is railed on all four sides.
Codes generally require a guard where the deck is more than about 30 inches above grade. Subtract stair openings and gates, and confirm the required height and baluster spacing locally.
Common deck joists are 2×6, 2×8, 2×10, or 2×12, and the right size depends on how far the joist spans between supports. Deeper joists span farther, so a longer unsupported run needs a bigger joist or a closer beam.
A 2×8 at 16 inches on center suits many mid-size decks, but this is set by span tables, not habit. Check the allowable span for your species, size, and spacing before you buy.
General Estimating Notice: This calculator estimates deck materials — decking, joists, ledger, beams, posts, footings, hardware, railing, and optional labor — from your deck dimensions, board and framing choices, and typical residential framing rules. Quantities are planning estimates and may differ from an engineered plan. Joist, beam, post, and footing sizes, footing depth, ledger attachment, and railing height must be confirmed against your local building code and span tables, or by a licensed professional. Freestanding, elevated, and multi-level decks vary. Prices use 2024–2025 U.S. figures and vary by region and grade. Confirm structure and code with a local pro — for planning purposes only.