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Deckcalc

The complete deck cost guide

I wrote this because the first time I priced a deck I stared at a $9,200 contractor quote for 280 square feet of pressure-treated. I had no idea whether that was fair. The guy wouldn't itemize. He kept saying "it includes everything," which is a polite way of saying don't ask questions.

So I built it myself. Three weekends, $3,800 in materials from Home Depot and Menards, one trip back for shorter joist hangers, and a Memorial Day 2020 deadline I hit with a day to spare. That deck is still standing. Straight. No sag. Every joist hanger properly nailed. I wrote this guide so the next homeowner staring at a $9,000 quote for a $4,000 job has the same math I wish I'd had.

If you just want a number, run your dimensions through the DeckCalc home page. Thirty seconds. No email. This page is the reasoning behind that number and the specifics that let you read a contractor bid without getting hosed.

What actually drives deck cost

Material first. Size second. Railings third. Elevation fourth. In that order, and it's not close. Two decks the same square footage can spread 3x apart on price, and 80 percent of that gap is material choice plus railing spec.

Pressure-treated pine installed runs about $22 per square foot. PVC (Azek, Wolf) runs $52. Same size, same elevation, same labor, and you just more than doubled the price by changing one dropdown. Add railings and stairs and the spread gets wider. A 320 sqft ground-level PT deck with wood railings and wood stairs comes in around $8,000. The exact same footprint in Trex Transcend with cable railings and composite stairs is closer to $22,000. Both are honest quotes. Both use the same formula. The inputs just aren't the same.

Knowing which inputs drive your number lets you read a contractor bid like a spreadsheet instead of a black box. When the quote says "$18,400" you should be able to reverse-engineer roughly how they got there.

Material deep dive

Six materials cover 98 percent of residential deck work. Here's how they really stack up.

Pressure-treated pine. The default for a reason. About $22 per sqft installed at ground level. Southern yellow pine treated with ACQ or MCA. Pros: cheap, at every Home Depot and Lowe's, easy to cut and fasten, YellaWood and Weathershield are both reliable brand stamps. Cons: warps if you don't stain it within the first year, the green tint looks terrible until you finish it, twists as it dries, and in Midwest freeze-thaw country the boards cup hard after year three. My first deck was PT. I'd do it again for a rental or a starter home.

Cedar. Western red cedar mainly. Around $30 per sqft installed. Pros: naturally rot-resistant, beautiful reddish tone, ages to a silver-gray if you leave it, smells like a sauna the first summer. Cons: soft wood means easy to dent, Texas cedar cost jumped 40 percent in 2024 when supply tightened, and it still needs a semi-annual cleaning and an annual coat of Penofin or equivalent oil stain or it greys unevenly. Cedar is the sweet spot if you want real wood without PT's warp problem.

Redwood. Around $36 per sqft. Mostly a West Coast material because freight kills the price east of the Rockies. Pros: the prettiest of the wood options, rot-resistant heartwood rivals cedar, ages to a beautiful deep silver-gray. Cons: supply is shrinking, old-growth grades are effectively gone, you're probably buying second-growth garden-grade which doesn't last as long as the 1970s reputation suggests. In California it still makes sense. In Ohio just pick cedar.

Composite, mid-tier. Trex Enhance, TimberTech Edge, Fiberon Sanctuary. Around $40 per sqft installed. Pros: never stain, never seal, most brands are 25-year limited warranties, dozens of colors. Cons: heats up in direct sun (Trex Enhance in a Dallas July is genuinely too hot to walk on barefoot at 3pm), scratches show if you drag patio furniture, mid-tier composite still has a visible wood-plastic texture that reads "fake." Still a solid middle-ground pick.

Composite, premium. Trex Transcend, TimberTech AZEK Vintage, Deckorators Voyage. Around $50 per sqft installed. Pros: best-in-class looks, cooler underfoot than mid-tier (some of these use a cap stock that reflects heat), 30 to 50-year warranties, color consistency is excellent. Cons: expensive, and if you damage a board replacement is hard to color-match years later since batches drift.

PVC (cellular vinyl). Azek, Wolf Serenity, TimberTech AZEK. Around $52 per sqft installed. Pros: zero organic content means zero rot, zero mold, zero insect damage. Lightweight. Warranty periods push 50 years. Cons: most expensive option, can feel plasticky underfoot, and in deep cold it gets brittle. The January 2024 polar vortex cracked some budget PVC boards in Minnesota; the premium brands held up fine.

Size and shape matter more than you think

Every sqft you add compounds four costs at once: decking material, joist material, fasteners, and labor. Going from 200 sqft to 400 sqft doesn't just double the price, it usually adds about 110 percent because waste factor, cut patterns, and labor efficiency all shift.

Shape also matters. A simple rectangle is cheapest to build. A rectangle with one bump-out for a grill station runs about 8 percent more for the same sqft because you've added corners, which means more ripped boards and more labor. A hexagon or octagon can run 20 to 25 percent more than a rectangle of the same area. Every time a board has to be cut at a non-90-degree angle you're adding time and waste.

The sweet spot for most backyards is a rectangle between 250 and 400 sqft. Big enough for a grill, a table for six, and four chairs. Small enough to keep the budget and build time reasonable.

Railings: the underestimated cost

Railings are the line item that surprises homeowners. A 320 sqft deck with 52 linear feet of wood railing adds roughly $1,560 in labor and material. Swap to aluminum railings and that same run is $6,240. Cable railings are closer to $9,360. Nobody talks about this until you get the quote.

Code requires a railing on any deck surface more than 30 inches above grade. So a ground-level (under 2 ft) deck can skip railings entirely and save thousands. A low-elevation (2 to 4 ft) deck that's borderline often gets built right at 29 inches to dodge the requirement, which is legal but looks weirdly short.

If you need railings, here's the honest ranking. Wood is cheapest and looks cheapest. Composite matches your decking and is the default upgrade most homeowners pick, about $70 per linear foot. Aluminum is the crisp, modern look at $120 per linear foot. Cable and glass are the premium options at $180 per linear foot and up. For a 320 sqft deck with 52 lf of railing, that's a $7,800 difference between wood and cable. Pick carefully.

Stairs add up fast

Each stair step installed runs $200 (wood) to $400 (PVC). A four-step run from a 3 ft elevated deck adds $800 to $1,600. A 12-step run from a second-story deck can add $2,400 to $4,800 before you've even touched the handrail.

Code is strict here. Rise between 4 and 7.75 inches. Run at least 10 inches. Maximum variance between any two risers is 3/8 inch. Handrail between 34 and 38 inches above the tread nose. Inspectors measure. I've seen a deck fail inspection and require stringer replacement because the top riser was 8.25 inches (finish flooring on the landing pushed it over). Plan the stair rise first, then size the rest of the deck to work with it.

Stair landing matters too. At the bottom of a stair run you need a concrete pad or compacted gravel, at least 3 ft by 3 ft. Most contractors include the pad; some don't. Ask.

Elevation and structural engineering

The calculator multiplies base cost by 1.00 (ground), 1.15 (low, 2-4 ft), 1.35 (mid, 5-8 ft), and 1.55 (high, 9 ft+). Those multipliers capture a lot of hidden work.

A ground-level deck can use 4x4 PT posts on simple concrete footings at frost depth. A 6 ft elevated deck needs 6x6 posts, bigger footings, and usually knee-bracing between posts. A 10 ft elevated deck needs a structural engineer's stamp in most jurisdictions, engineered beams (LVL or steel), and sometimes a dedicated footing inspection separate from the framing inspection. Each step up adds inspections, paperwork, and material cost.

Hot tubs are their own category. A hot tub adds 3,000 to 5,000 pounds of live load when full, and almost every deck that supports a hot tub needs engineer-stamped drawings. Don't spec a hot tub on an existing deck without having the structural capacity checked. I've watched a deck fail under a 450-gallon hot tub that seemed fine on paper.

Permits, inspections, and code

Most U.S. jurisdictions require a permit for any deck attached to a house, any deck taller than 30 inches, and any deck over 200 sqft. Permit cost is usually $100 to $500. Process is an online application plus a set of drawings, then one to three weeks of review.

Inspections happen in stages. Footings first (before pouring concrete). Framing before deck boards go on. Final inspection after railings and stairs are complete. Miss a stage and you redo the inspection, which costs time and sometimes money. Every inspection I've had went smoothly because I'd walked the site with the inspector before he showed up officially. Fifteen minutes of prep saves a second trip.

HOAs have their own rules. Even if the city approves a composite deck, your HOA may require wood to match the neighborhood. Read the CC&R. Submit architectural approval in writing. Get written approval, not a verbal "sounds fine from Dave on the committee."

The deck you don't permit is the deck your insurance doesn't cover and your buyer's home inspector flags in three years.

DIY vs contractor (the real labor percentage)

Labor is 55 percent of a standard contractor bill. That's the number people argue about, but it's the Homewyse and Fixr consensus and my own three-quote experience matches it.

DIY eliminates labor entirely (it's your time) but still requires materials, tool rental, and a bit of "I didn't plan for that" cushion. The calculator uses a 0.35 multiplier for DIY, meaning your total drops to roughly 35 percent of the contractor price. Materials plus rental, roughly.

What you're trading. For 320 sqft ground-level PT: 25 to 35 labor hours across three weekends for two people. Post holes, framing, boards, railing, stairs, cleanup. If the deck is elevated or over 400 sqft, double it. If you've never used a DeWalt impact driver or set a joist hanger before, triple it. The learning curve is real.

When DIY makes sense: ground-level or low, under 400 sqft, simple rectangle, you or a friend have basic framing experience, you own or can borrow a Makita chop saw, a Bosch circular, a framing square, and a level. When it doesn't: elevated, attached to the house, over 400 sqft, or you don't have three consecutive weekends to commit.

Lifespan and maintenance cost (10-year TCO)

Ten-year total cost of ownership is where composite and PVC start to look smart. Here's the math for a 320 sqft deck.

Pressure-treated: $7,040 installed + $128/year in stain, seal, and board replacement (about 10 percent board swap every 10 years) = $8,320 over 10 years.

Cedar: $9,600 installed + $160/year in stain and cleaner = $11,200 over 10 years.

Composite mid (Trex Enhance): $12,800 installed + $15/year in cleaner = $12,950 over 10 years.

Composite premium (Trex Transcend): $16,000 installed + $10/year = $16,100 over 10 years.

PVC (Azek): $16,640 installed + $5/year = $16,690 over 10 years.

PT still wins 10-year. At 25 years the picture flips hard. Composite and PVC maintenance stays near zero while PT's board replacement rate accelerates past year 15. The stay-long horizon calculation is where the composite premium pays back.

The formula this calculator uses

No hidden logic.

  • Base material price per sqft: PT $22, cedar $30, redwood $36, composite mid $40, composite premium $50, PVC $52.
  • Elevation multiplier: ground 1.00, low 1.15, mid 1.35, high 1.55.
  • Install multiplier: contractor 1.00, DIY 0.35.
  • Railings: $30/lf (wood), $70/lf (composite), $120/lf (aluminum), $180/lf (glass or cable).
  • Stairs: $200 (wood), $300 (composite), $400 (PVC) per step.
  • Permit: $200 flat if toggled on.
  • Site prep: $2 per sqft if toggled on (grading, layout, string-lining).
  • Old deck removal: $4 per sqft if replacing.
  • Display range: midpoint × 0.88 to midpoint × 1.20. Decks swing harder than fences because so many variables compound.

Numbers pull from Homewyse's itemized cost database, Fixr's 2025 material and labor tables, Decks.com, and the specific per-foot ranges Trex and TimberTech publish in their own calculators. Three test cases validated against real published contractor quotes.

Hidden costs contractors forget to mention

Sales tax. Most quotes are pre-tax. On a $15,000 deck in Texas that's another $1,200.

Dumpster and disposal. If you're replacing an existing deck, demolition waste fills a 10-yard dumpster fast. $350 to $600 depending on market.

Landscaping repair. The crew will trample your grass, crush bushes near the footings, and leave concrete dust. Budget $200 to $500 for reseeding and replanting.

Stain and sealer (for wood decks). Not usually included in the deck bid. A 320 sqft deck needs 3 gallons of Ready Seal or Cabot (around $150) and a full day of your time.

Gate hardware, post caps, lighting. The "we'll include nice post caps" line usually means $12 plastic caps. If you want the Simpson Strong-Tie copper caps, add $8 each across 12 posts. LED post caps from Deckorators or Trex add $25 to $40 each.

Tree removal. If a tree or two has to come out for the deck footprint, that's $400 to $1,500 per tree and rarely included in the base bid.

Electrical. Adding an outlet on a deck post requires a licensed electrician, GFCI protection, and an inspection. $300 to $800 for a single outlet.

Go get quotes

Run your numbers through the DeckCalc home page, write the range down, then get three itemized contractor bids. Walk the property with each estimator. Ask for a bid that separates materials, labor, railings, stairs, permit, and any adders. The one who refuses to itemize is the one you're not hiring. Questions this guide didn't answer? The FAQ covers 15 more, and the blog goes deep on specific scenarios.