Deck Cost Calculator — Build Budget by Size & Material
Estimate what a new deck will cost. Enter each deck section, pick your decking material and whether it's contractor-built or DIY, add railing and stairs, and get a full budget with an all-in per-square-foot figure — plus a downloadable estimate PDF.
| Section | Dimensions | Area | Decking $ |
|---|---|---|---|
| Run the calculator to see your takeoff | |||
How to use the deck cost calculator
Four quick steps turn your deck’s size and finishes into a full build budget — decking, railing, stairs, permit, and contingency — with an all-in per-square-foot figure and a downloadable estimate.
Pick material & build
Choose pressure-treated, composite, or PVC, and whether it’s contractor-built or DIY. The rate auto-fills — edit it.
Enter the deck size
Add each deck section as length × width, with a quantity for identical ones. Landings and wraparounds get their own rows.
Add railing & stairs
Enter railing lineal feet and the number of steps, plus a permit fee and a contingency for surprises.
Read results & save a PDF
Get the project total, cost by component, and all-in per ft², with a section takeoff — then download an estimate.
How the deck cost is calculated
The deck surface is area × rate; railing and stairs are priced separately, then permit and contingency finish the budget. Here is the exact math the calculator runs.
Worked example — 16×12 main + 8×8 landing, pressure-treated, contractor, 40 lf railing, 4 steps
Area: 192 + 64 = 256 ft² · Decking: 256 × $35 = $8,960
Railing: 40 × $40 = $1,600 · Stairs: 4 × $70 = $280
Subtotal $10,840 + $200 permit = $11,040
With 10% contingency: $11,040 × 1.10 = $12,144
≈ $12,144 all-in — about $47/ft². DIY would run roughly half.
Deck cost charts
Handy lookups for material rates, decking cost by deck size, add-on pricing, and what drives the all-in figure. These are national-average ballparks — editable, and no substitute for a quote.
| Material | Cost / ft² | Notes |
|---|---|---|
| Pressure-treated wood | ~$35 | Budget; needs sealing & upkeep |
| Composite | ~$50 | Low-maintenance, long life |
| PVC / capstock | ~$65 | Premium, lightest maintenance |
Installed (material + labor), covering the deck surface plus framing and footings. DIY runs roughly half. Railing and stairs are extra.
| Deck size | Area | Pressure-treated | Composite |
|---|---|---|---|
| 10 × 12 ft | 120 ft² | ~$4,200 | ~$6,000 |
| 12 × 16 ft | 192 ft² | ~$6,720 | ~$9,600 |
| 16 × 16 ft | 256 ft² | ~$8,960 | ~$12,800 |
| 16 × 20 ft | 320 ft² | ~$11,200 | ~$16,000 |
| 20 × 20 ft | 400 ft² | ~$14,000 | ~$20,000 |
Decking surface only. Add railing, stairs, permit, and contingency — those push the all-in figure higher.
| Item | Typical rate |
|---|---|
| Railing — wood | $20–30 / lineal ft |
| Railing — composite / metal | $40–70 / lineal ft |
| Stairs | $50–100 / step |
| Permit | varies (~$200) |
| Footings & framing | included in the deck rate |
Railing runs the perimeter minus the house side and stair opening. Together, railing and stairs often add 15–25% to the decking cost.
| Factor | Effect |
|---|---|
| Material | PT < composite < PVC |
| Build type | DIY ≈ half (materials, your labor) |
| Deck height | Taller = more posts, footings, bracing |
| Railing & stairs | Added per lineal ft / per step |
| Site & access | Slope, soil, access, old-deck removal |
The contingency is there to absorb footing and site surprises a size-and-material estimate can’t see in advance.
Everything the calculator works out
One deck layout gives you a full build budget — broken down by component and expressed as an all-in cost per square foot.
Key figures behind a deck budget
Built for planning a deck
From a homeowner’s first budget to a builder’s quick bid, the same calculator turns a layout into a number.
Planning a deck and wants a realistic all-in cost, by material, before calling builders for quotes.
- Enter each deck section
- Compare PT, composite & PVC
- See the all-in per ft²
Building it themselves and wants a materials-only ballpark to compare against a contractor bid.
- Switch build type to DIY
- Add railing & stair counts
- Still budget the permit
Wants a quick section-by-section estimate to share, then confirms with a site visit.
- Set your own rates
- Break out railing & stairs
- Hand the PDF to the client
7 tips for a realistic deck budget
A deck budget is more than the boards underfoot. These points keep the estimate honest — and remember it’s a ballpark, not a bid.
Deck cost calculator FAQ
The cost, material, and budgeting questions people ask most before building a deck.
Cost is driven by area, material, and add-ons. Multiply the deck’s square footage by an installed rate, then add railing, stairs, a permit, and a contingency.
Example: a 256 ft² pressure-treated contractor-built deck with 40 lf of railing and four steps is about $8,960 decking + $1,600 railing + $280 stairs, or roughly $12,144 all-in with permit and 10% contingency — about $47/ft².
Composite and PVC cost more, and raised decks cost more than ground-level ones. Get written quotes locally.
Start with an installed rate for your material — roughly $35/ft² pressure-treated, $50 composite, $65 PVC — and multiply by the deck area.
That rate covers the decking surface plus framing and footings. Railing (per lineal foot), stairs (per step), permit, and contingency stack on top, so the all-in per ft² runs higher than the base rate.
In the example, a $35/ft² base becomes about $47/ft² all-in.
It’s a trade-off between up-front price and upkeep.
Pressure-treated (~$35/ft²) is cheapest but needs cleaning, sealing, and eventual board replacement. Composite (~$50/ft²) costs more up front but resists rot and fading with little maintenance. PVC / capstock (~$65/ft²) is priciest and lowest-maintenance, with the longest life.
For a tight budget, pressure-treated wins; for lowest lifetime upkeep, composite or PVC often pays back. Weigh how long you’ll keep the home.
Composite typically runs about 40% more per square foot installed than pressure-treated wood — roughly $50/ft² versus $35 in the defaults.
On a 256 ft² deck that’s about $12,800 in composite decking versus $8,960 in pressure-treated, before railing and stairs. The gap narrows over time, since composite skips the staining, sealing, and board replacement wood needs.
Prices vary by brand — entry-level composite is closer to wood, premium capped composite and PVC sit higher.
Roughly — because labor is a large share of a deck’s price. The DIY setting applies about half the installed rate, approximating a materials-only cost with your own labor.
So a deck that costs ~$12,000 installed might run closer to $6,000 in materials if you build it. But that assumes the tools, time, and skill, and it doesn’t remove the permit, footings, or code requirements.
A deck is structural — if it’s raised, a mistake can be dangerous. Be honest about your ability, and pull the permit either way.
Both are priced separately from the deck surface. Railing runs about $20–30 per lineal foot for wood and $40–70 for composite or metal, along the perimeter minus the house side and stair opening.
Stairs cost roughly $50–100 per step, including stringers and framing. Four steps is a few hundred dollars; a tall raised deck with a long stair run is much more.
Together, railing and stairs can add 15–25% on top of the decking cost — don’t budget on the surface alone.
Usually yes. Most jurisdictions require a permit for a deck attached to the house or above a certain height, because a deck is a structural, load-bearing element and a collapse is a serious safety risk.
The permit and inspection confirm the footings, framing, ledger attachment, and railing meet code. Ground-level, freestanding, or very small platforms are sometimes exempt, but rules vary — check your local building department.
The fee is a small part of the budget; skipping a required permit can mean fines, forced removal, and resale problems.
Beyond size and material, the big drivers are height and site conditions.
A raised deck needs taller posts, deeper footings, and more framing than a ground-level one. Difficult access, sloped or rocky ground, hard-to-dig soil, and removing an old deck all add labor. Design complexity — angles, multiple levels, built-ins, fancy railing — adds too.
This calculator gives a size-and-material ballpark; the contingency absorbs footing and site surprises. A site visit and written quote capture what a calculator can’t.
Budget Estimate — Not a Quote: The default rates are national-average installed prices and vary widely by material grade, deck height, footing depth, framing, railing style, site access, and region. This calculator produces a size- and material-based budget only — it is not a contractor quote, and it does not size or design the structure. A deck is a load-bearing structure: footings, framing, ledger attachment, and railing must meet local building code and are the responsibility of a licensed builder or engineer, and most decks require a permit. Confirm the design and get written, itemized quotes before building. For planning purposes only.