Free online deck cost calculator and estimator.
Estimate the installed cost of a new deck based on size, height, decking material, railing, and ZIP code. Get an instant low-high planning range and midpoint, then compare scenarios before you talk with a contractor. This is a planning tool, not a quote or bid.
Start the estimator ↓See a low-high planning range plus a midpoint for faster early budgeting.
Size, height, decking, railing, and local cost differences all change the outcome.
Real contractor pricing can be materially higher or lower after the site and scope are reviewed.
Start with a budget expectation before you talk to a builder.
The estimator is meant to help homeowners sense-check a potential project. It is especially useful when you are comparing materials or wondering whether a raised deck is likely to land closer to one budget band or another.
Start here.
Enter the project details below, then click the button to calculate your rough ballpark range.
Use the output as a conversation starter, not a construction commitment.
The goal here is to help homeowners set expectations before meeting with a contractor. The most useful way to use the tool is to compare scenarios — for example, composite vs. premium composite, or a low deck vs. a higher elevated deck with more structure.
Try a few scenarios.
Changing materials, height, railing, or ZIP code can reveal which design decisions drive the budget the most.
The real property matters.
Slopes, access, demolition, drainage, or unusual foundations can push a final contractor number noticeably above or below the estimate.
Then talk to a builder.
A real quote should reflect the actual site, dimensions, scope, included items, engineering, and finish selections.
Typical deck cost examples from the Deckari model.
These examples are calculated from the same model used by the interactive estimator above. They are provided as crawlable planning examples so homeowners can compare common sizes and materials even before entering project details.
| Deck size | Pressure-treated wood | Composite | Premium composite | PVC / cellular PVC |
|---|---|---|---|---|
| 12 × 12 144 sq ft |
$6,600 – $9,500 | $9,100 – $12,300 | $10,000 – $13,400 | $11,000 – $14,400 |
| 12 × 16 192 sq ft |
$8,200 – $11,600 | $11,500 – $15,300 | $12,800 – $16,700 | $14,000 – $18,100 |
| 16 × 20 320 sq ft |
$12,100 – $16,400 | $17,600 – $22,600 | $19,700 – $24,900 | $21,800 – $27,200 |
| 20 × 20 400 sq ft |
$14,300 – $19,000 | $21,300 – $26,800 | $23,900 – $29,700 | $26,500 – $32,600 |
Example assumptions: national baseline, attached deck, 3 feet above grade, pressure-treated wood posts, composite railing, automatically estimated railing length, and no site-specific demolition, engineering, permit, drainage, lighting, utility, or access allowance. Actual contractor pricing may be materially higher or lower.
How the Deckari deck cost calculator works.
The calculator builds a planning estimate from several modeled cost components rather than applying one flat price per square foot to every project.
Start with the footprint.
The model calculates deck area from width × length and applies a national baseline installed-cost range before material adjustments.
Adjust for the walking surface.
Pressure-treated wood, cedar, redwood, composite, premium composite, PVC, tropical hardwood, and bamboo use different material factors.
Add elevated-deck costs.
For decks above grade, the model adds costs for modeled footings or piers, posts, stairs, and additional bracing at greater heights.
Price railing by linear foot.
Railing is estimated from deck geometry or a manually entered length, with separate modeled rates for wood, composite, aluminum, cable, and glass.
Apply a regional adjustment.
A five-digit U.S. ZIP code can apply a regional cost multiplier. Leaving ZIP blank uses the model's national baseline.
Return low, high, and midpoint values.
The calculator combines the modeled components, applies the regional factor, and rounds the result into an easy-to-use planning range.
Common questions about deck construction cost.
These answers explain how common deck-cost questions map to the estimator above. Use the interactive calculator for a project-specific planning range.
How much does a 12×16 deck cost?
Using the example assumptions above, Deckari's model estimates a 12×16 deck at about $8,200–$11,600 with pressure-treated decking, $11,500–$15,300 with composite, $12,800–$16,700 with premium composite, or $14,000–$18,100 with PVC.
How much does a 300-square-foot deck cost?
Shape matters because it changes railing length. As one example, a 15×20-foot, 3-foot-raised attached composite deck with composite railing at the national baseline is about $16,700–$21,500 in the Deckari model.
How much does composite decking cost installed?
Installed composite deck cost depends on more than the decking boards. Size, deck height, substructure, stairs, railing, location, access, demolition, engineering, and site conditions can all affect the final number. Use the calculator above to model those major inputs.
How much does a raised deck cost?
A raised deck generally costs more in this model because it adds posts or piers, footings, stairs, and—at greater heights—additional bracing to the base deck cost.
Does deck height affect the cost?
Yes. Increasing height increases the modeled cost of the supporting structure and stairs. Higher decks can also require additional bracing, and real projects may require engineering or more complex foundations that are outside this planning model.
How much does deck railing add?
Railing cost depends on both linear footage and material. The estimator supports wood, composite, aluminum, cable, and glass railing and can estimate railing length from the deck dimensions or use a length you enter manually.
How much does a deck cost per square foot?
A single per-square-foot number can be misleading. Deckari starts with a modeled area-based deck cost, then separately accounts for material, elevation, structure, stairs, railing, and region. Those additions mean the effective total cost per square foot changes from project to project.
Does deck construction cost vary by ZIP code?
Yes. Entering a five-digit U.S. ZIP code applies the calculator's regional adjustment. Leaving the field blank uses the national baseline, which is useful for comparing design options without a location adjustment.
Want to discuss a real outdoor living project?
Tell Deckari what you want to build, where the project is located, and your approximate budget and timing. We will review the information and determine whether there may be a suitable builder fit for the work.
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