Deck Cost Per Square Foot

Deck cost per square foot typically runs $31–$82 per square foot installed in 2026, at national-average prices, depending mainly on the decking material. Pressure-treated pine sits at the low end, capped composite in the middle, and premium hardwood or PVC at the top end. All of those ranges include framing, footings, railing, stairs, and disposal of an old deck where one is being replaced, plus permits, sales tax, and a 10% contingency.

This guide breaks that per-square-foot price down by material and by deck size, explains how to measure your own deck, and shows why two quotes for the same footprint can land far apart. It is written for a homeowner pricing a new deck or checking a contractor's quote. For a total based on your own dimensions and material choice, use the deck cost calculator.

Cost at a glance

The table below uses the site's own calculator figures. The per-square-foot price is the installed price, not the price of boards alone, so it already reflects framing, footings, fasteners, railing, and labor.

A note on the edges of those ranges: the low end of each range assumes a straightforward, low-to-the-ground deck with a simple railing and standard stairs. A tall deck, a deck with a lot of railing, angled boards, picture-frame borders, or multiple stair runs will push toward the high end, whatever material you choose. Labor rates also vary by metro, and can move these national averages noticeably in either direction; see how we calculate costs for what is included.

Cost by deck size

Total cost rises with size, but not in a straight line, because some costs are fixed. Footings, a ledger connection to the house, permits, and getting a crew and materials to the site cost roughly the same whether the deck is 144 sq ft or 500 sq ft. That is why small decks look expensive per square foot and large decks look cheaper per square foot, even with the same boards.

These totals are for a mid-range capped composite deck at national-average prices, which is why the medium size matches the composite row in the table above. A pine deck of the same size will come in lower, and a premium hardwood or PVC deck higher. If you are comparing a total quote to a per-square-foot quote, convert one to the other before you judge either: divide the total by your deck's square footage, and check whether the total includes railing, stairs, and tear-off.

How to measure your project

Measure the deck you want, not the deck you have, if the two differ. For a rectangle, multiply length by width. A 16 ft by 20 ft deck is 320 sq ft. For an L-shaped or multi-level deck, split it into rectangles, measure each one, and add them together. Measure to the outside edge of the decking, including the area under the railing, since that is the area the crew builds and boards.

A few measuring details that change the price:

• Height matters more than area alone. A deck close to the ground needs short posts and one short stair run. A deck 8 ft or more above grade needs taller posts, more bracing, longer stairs, and more railing, all of which add labor and material beyond the square footage.
• Stairs are not free square footage. Count each stair run separately when you compare quotes, and note whether the quote includes one run or two. A wide stair to a yard, plus a second set to a side gate, can add a meaningful amount to a job that looks identical on a floor plan.
• Railing is priced by length, not by area. A deck on three open sides has far more railing than a deck tucked into a corner of the house with only one open side. When a per-square-foot quote seems high, check how much railing it includes and what type: standard wood balusters cost less than aluminum balusters, cable railing, or a drink rail on top.
• Board direction and pattern add waste. Diagonal boards, herringbone insets, and picture-frame borders look good but use more material and take longer to lay than straight runs. Ask whether the quote includes a waste allowance for the pattern you chose, typically around 10% for straight runs and more for angled work.

If you are replacing an existing deck, measure that deck too and tell the contractor whether the old framing, footings, or stairs are staying. Reusing sound framing can lower the price, but a contractor should not promise to reuse it before inspecting it, and any quote that assumes reuse should say so in writing.

Why the per-square-foot price changes with size

Think of a deck quote as two parts: fixed costs and per-square-foot costs. The per-square-foot part is mostly boards, joists, and the labor to install them. The fixed part includes permits and inspections, concrete pier footings, the ledger board connection to the house, demolition and hauling of an old deck, and mobilization. On a 144 sq ft deck, those fixed costs are spread over few square feet, so the effective price per square foot is high. On a 500 sq ft deck, the same fixed costs are spread over a much larger area, so the price per square foot drops.

That has a practical consequence: adding 50 sq ft to a large deck is cheaper per square foot than building a tiny deck in the first place. It does not mean a bigger deck is a bargain overall — the total still rises — but it does mean you should not judge a small-deck quote by comparing its per-square-foot rate to a neighbor's large-deck rate. Compare totals for the same size, material, height, railing, and stair count instead.

Shape matters as well. A simple rectangle is the cheapest shape per square foot. Bump-outs, curved edges, and multiple levels add framing complexity, more cuts, and more railing corners, even when the total area is unchanged. If a design change adds little usable space but a lot of corners, expect the per-square-foot price to rise.

What's included vs what costs extra

A complete deck quote should cover framing, beams and joists, concrete pier footings, decking surface boards, the railing and baluster system, stairs and stringers, and demolition and hauling of an old deck. The benchmark ranges in this guide include those items, along with permits, disposal, sales tax, and a 10% contingency. If a quote is well below these ranges, the first thing to check is what it left out, not whether the contractor is simply cheaper.

Items that are often left out or billed separately include:

• Ledger flashing. The ledger board is where the deck attaches to the house, and water getting behind it can rot the band joist of the house itself. Proper Z-flashing and attachment to the house framing with structural screws should be specified in the quote. Fixing a failed ledger later typically runs $400–$800, and the rot it causes can cost far more.
• Footing depth. Footings must reach below the local frost line, which varies by municipality. A quote should state the footing depth it is based on, rather than leaving it to be discovered during inspection.
• Under-deck work. A weed barrier and gravel bed under a new deck, to keep weeds and standing water away, typically runs $350–$700 and is easy to skip on paper and hard to add later.
• Fasteners for treated wood. Pressure-treated lumber requires stainless steel or approved coated fasteners. Standard fasteners corrode in contact with treated wood, so a quote should name the fastener type.
• Permits and inspections. Most decks need a building permit, and the permit and inspection sign-offs should be included in the quote rather than left to the homeowner.
• Lighting and extras. Integrated LED stair lighting, a drink rail, and privacy screens are not in the base ranges. Premium hardwood and PVC decks in the table above include drink rail and stair lighting, which is part of why their per-square-foot price is higher.

Before you sign, paste the quote into the Quote Checker to see what is missing. A quote that spells out footing depth, flashing, fastener type, railing type, stair count, and permit responsibility is easier to compare than a cheaper quote that leaves those items vague. For a fuller look at total deck costs, including material trade-offs, see how much it costs to build a deck and composite vs wood deck cost.

Worked example: a 16 ft by 20 ft composite deck

Take a medium deck, 16 ft by 20 ft, which is 320 sq ft, built with capped composite decking, hidden fastener clips, and an aluminum baluster railing, close to ground level with one stair run.

Multiply the area by the composite per-square-foot range: 320 sq ft x $42–$58 = $13,440–$18,560. Rounded, that is $13,500–$18,500, which matches the calculator's typical project cost for this size and material. That total includes framing, footings, railing, stairs, tear-off of an old deck if there is one, permits, disposal, sales tax, and contingency.

Now change one variable at a time to see how the total moves. Switch the same deck to pressure-treated pine, and the math becomes 320 sq ft x $31–$42 = $9,920–$13,440, or roughly $9,800–$13,500. Switch it to premium ipe or PVC, and it becomes 320 sq ft x $60–$82 = $19,200–$26,240, or roughly $19,000–$26,000. Raise the deck well above grade, add a second stair run and a long railing run, and expect to land toward the high end of whichever material range you chose, before any extras such as lighting.

Use this same multiplication for your own deck: your measured area, times the per-square-foot range for your material, gives a planning total. Then adjust up for height, railing length, stairs, and pattern, and check the result against the deck cost calculator for your dimensions.

Permits and timeline

Most cities require a building permit for a new deck, especially when it attaches to the house or stands more than a short distance above grade. A freestanding, very low platform may be exempt in some places, but that is a local rule, not a general one. Check with your local building department before work starts, and make sure the quote states who obtains the permit and who pays the fee. Work done by a licensed, insured contractor is the safe route for a structural, attached deck, and the permit inspection is what confirms the footings, ledger, and framing meet code.

Timeline depends on size, height, weather, and permit review, which varies by city. A straightforward, low deck can be framed and boarded in a matter of days once materials are on site and the permit is in hand, while a large, tall, or multi-level deck takes longer. The slowest part is often not the building but the wait for permit approval and for inspections at the footing and framing stages, so ask the contractor how permit timing is handled in the schedule rather than assuming a start date is a finish date.

Keep the permit sign-off and material warranties when the deck is done. Composite and PVC need little more than periodic cleaning, while pine needs regular sealing or staining.