Deck Cost Calculator

A deck cost calculator that prices the build line by line: decking, substructure, footings, guard, stairs and permit, with typical 2026 US installed ranges.

By CalcBuilt Editorial TeamUpdated September 9, 2026Formulas checked against manufacturer specs, see how we calculate.

Quick answer: To budget a deck, price the decking surface, the substructure with its footings, the guard, the stairs and the permit as separate line items instead of one blended rate. A 16 x 12 ft ground level deck in capped composite, with a composite guard and four steps, typically runs $7,800 to $15,700, or about $41 to $82 per square foot.

Your measurements

Deck from above: boards run the length, joists run the width beneath them at a fixed spacing.

Deck lengthftThe side along the house on a ledger deck. Length and width set the surface area, which drives decking, framing and skirting.Deck widthftThe distance out from the house, which is the joist span. Past 14 ft the joists go to 2x12 or the frame needs a second beam.Decking materialRates cover boards, fasteners and the labor to lay them, not the frame. Hidden clips add roughly $0.60 to $1.20 per sq ft over face screws.Deck heightOver 30 in the deck needs taller 6x6 posts, a deeper beam, diagonal bracing and a guard, and IRC R312.1 stops making the guard optional.Guard typePriced along the open sides only, less one stair opening. This is the line that swings a deck budget the most on a small footprint.Stairs (number of steps)Count risers, not treads. A 30 in drop is about 4 steps at a 7.5 in riser. Stairs carry their own stringers, footings and a graspable handrail.ExtrasLow voltage stair and post lights run on a transformer and a dedicated circuit. Skirting is priced per foot of open perimeter.Permit and footingsEngineered means helical piers or a stamped footing design, which is what expansive clay, fill or a high deck usually triggers.

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Results

Total range: $7,800 to $15,700; 192 sq ft of capped composite decking, ground level, with a composite guard on 36 ft of edge and 4 steps
Cost per square foot: $41 to $82 per sq ft; The way builders quote a deck. Guard, stairs and footings sit inside this figure, so it lands well above any decking-only rate
Decking surface: $2,688 to $4,992; 192 sq ft at $14.00 to $26.00 per sq ft installed, boards and fasteners only
Substructure, footings and permit: $2,678 to $5,872; Ledger, beam, joists and hangers at $9.00 to $16.00 per sq ft, plus 5 footings at $150 to $400 each. Planning estimate: the local code and the inspector govern footing depth and the ledger
Guard, stairs and extras: $2,420 to $4,820; 36 ft of guard at $55.00 to $105.00 per linear ft, 4 steps at $110 to $260 each
Composite versus treated over 15 years: $1,536 to $2,880 more up front; Cleaning and restaining 192 sq ft six times in 15 years runs $2,880 to $5,760 at $2.50 to $5.00 per sq ft a cycle, so the composite surface pays its upcharge back

Deck Cost formula

Decking = Area x decking rate per sq ft (treated $6 to $11, composite $14 to $26)
Substructure = Area x framing rate + Footings x cost each + permit
Guard = (Length + 2 x Width - stair opening) x rate per linear foot
Total = Decking + Substructure + Guard + Steps x $110 to $260 + extras

Worked example

A 20 x 14 ft deck 5 ft off the ground in cedar, with stainless cable guard, 8 steps and stair lighting, permitted with poured piers. Area is 280 sq ft. Cedar decking at $9 to $16 is $2,520 to $4,480. Elevated framing at $14 to $24 is $3,920 to $6,720, and 6 footings at $250 to $600 add $1,500 to $3,600.

The guard runs 20 + 28 - 4 = 44 linear feet, so cable at $95 to $190 is $4,180 to $8,360. Eight steps add $880 to $2,080, lighting $700 to $2,000 and the permit $200 to $800. The total lands near $13,900 to $28,000, or $50 to $100 per square foot. The cable guard alone is 30 percent of the low end.

Quick reference

Typical 2026 US installed ranges by deck line item
Line item	Basis	Typical range
Pressure treated decking	Per sq ft of surface	$6 to $11
Western red cedar decking	Per sq ft of surface	$9 to $16
Capped composite decking	Per sq ft of surface	$14 to $26
Cellular PVC decking	Per sq ft of surface	$18 to $34
Ipe or tropical hardwood	Per sq ft of surface	$20 to $38
Substructure, ground level	Per sq ft	$9 to $16
Substructure, elevated	Per sq ft	$14 to $24
Poured pier footing	Each	$150 to $400
Wood guard	Per linear foot	$25 to $50
Stainless cable guard	Per linear foot	$95 to $190

Where the money actually goes

A deck is four budgets in one. The decking surface tracks square footage and the material you pick. The substructure tracks square footage too, but jumps once the deck clears 30 inches and needs 6x6 posts, a deeper beam and diagonal bracing. The guard tracks perimeter, not area. Stairs track riser count. That is why two 200 square foot decks can differ by $10,000.

Perimeter is the trap. A 16 by 12 foot deck is 192 square feet with 40 feet of open edge. A 24 by 8 foot deck is the same area with 40 feet of edge and a longer ledger. Doubling the area of a square deck adds far less guard than doubling a narrow one, so a compact rectangle costs less per square foot than a long, thin deck of the same size.

Reading a deck bid

Ask for the bid broken into framing, decking, guard, stairs and footings, and ask which decking line the numbers use. Trex publishes $15 to $30 per square foot for composite material including substructure and fasteners, so a materials-only figure near that is normal and the labor sits on top. A bid quoting one blended rate with no takeoff is guessing.

Check the hardware while you are at it. Treated lumber corrodes electroplated connectors, so hangers, bolts and screws have to be hot dipped galvanized G185 or ZMAX, or stainless, and never mixed. Guard posts need a hold-down rated for 1,800 lb (DCA 6). Those parts are a few hundred dollars on a typical deck and are the first things a cheap bid drops.

What this calculator leaves out

Site work: tree or shrub removal, regrading, hauling equipment through a narrow side yard, and rock that turns a two hour footing dig into a full day. Demolition of an existing deck and the dumpster to haul it. Under-deck drainage, a roof or pergola over the deck, an outdoor kitchen, a hot tub and the reinforced framing one needs, and the electrical circuit that lighting or a receptacle requires (IRC E3901.9 calls for a receptacle on a deck over 20 sq ft).

It also leaves out finishes on wood decking. Pressure treated and cedar want a cleaning and a fresh coat of penetrating stain every two to three years, which is where the composite comparison row comes from. Composite and PVC skip that but still need a wash. Stamped engineering, soil testing and any variance for a setback or an easement are separate professional fees.

Code limits that apply

IRC R507.9.1.3
Ledger held by 1/2 in lags or bolts in two staggered rows, spaced by joist span
If you miss it: A ledger on nails or screws is the classic deck collapse; the inspector counts and measures every bolt before sheathing
IRC R312.1checked
Guard 36 in min wherever the deck surface is more than 30 in above the grade below
If you miss it: An elevated deck budgeted with no guard needs posts, rails and hold-downs added, typically thousands after the fact
IRC R105.2checked
Permit exempt only under 200 sq ft, under 30 in high, unattached, not at the exit door
If you miss it: Unpermitted deck work is excluded from the appraisal and gets flagged by a buyer's inspector at sale
IRC R403.1.4
Footings bear 12 in min below undisturbed grade and below the local frost line
If you miss it: A shallow pier heaves each winter and the frame racks away from the ledger; footings are inspected before the pour
AWC DCA 6 Table 2
Southern pine 2x8 at 16 in OC spans 11 ft 10 in; 2x10 reaches 14 ft 0 in
If you miss it: A 14 ft wide deck framed with 2x8 bounces and gets rejected, so every joist and the beam are rebuilt
AWC DCA 6 Table 4
6x6 posts, with footing diameter set by beam span and joist span, up to 31 in round
If you miss it: An 18 in pier under a long beam settles and the deck slopes; the fix is jacking the frame and repouring

Provision	Limit	If you miss it
IRC R507.9.1.3	Ledger held by 1/2 in lags or bolts in two staggered rows, spaced by joist span	A ledger on nails or screws is the classic deck collapse; the inspector counts and measures every bolt before sheathing
IRC R312.1checked	Guard 36 in min wherever the deck surface is more than 30 in above the grade below	An elevated deck budgeted with no guard needs posts, rails and hold-downs added, typically thousands after the fact
IRC R105.2checked	Permit exempt only under 200 sq ft, under 30 in high, unattached, not at the exit door	Unpermitted deck work is excluded from the appraisal and gets flagged by a buyer's inspector at sale
IRC R403.1.4	Footings bear 12 in min below undisturbed grade and below the local frost line	A shallow pier heaves each winter and the frame racks away from the ledger; footings are inspected before the pour
AWC DCA 6 Table 2	Southern pine 2x8 at 16 in OC spans 11 ft 10 in; 2x10 reaches 14 ft 0 in	A 14 ft wide deck framed with 2x8 bounces and gets rejected, so every joist and the beam are rebuilt
AWC DCA 6 Table 4	6x6 posts, with footing diameter set by beam span and joist span, up to 31 in round	An 18 in pier under a long beam settles and the deck slopes; the fix is jacking the frame and repouring

Rows marked checked produce a warning in the results when an entry crosses the limit. The others are on the plans or on site and this calculator does not test them. Local amendments can be stricter; the adopted edition and the inspector govern.

Mistakes that cost money

A single price per square foot of deck surface buries the guard, stairs and footings, which are half the cost on a small deck.
Composite boards on a treated frame still need the frame rebuilt in 15 to 25 years; the surface outlives the joists under it.
DCA 6 requires a footing within 5 ft of the house foundation to bear at the same elevation as the house footing, which doubles the digging.
Tearing out an old deck is a separate line: demolition and disposal typically runs $5 to $12 per square foot plus the dumpster.
A deck over a patio or walkout needs an under-deck drainage system, typically $12 to $25 per square foot, and no decking quote includes it.
Ipe and other dense hardwoods need pre-drilled stainless fasteners and carbide blades, which adds a day of labor per 200 square feet.

Key facts

Trex puts composite deck material at $15 to $30 per square foot covering substructure, decking, hardware and fasteners, before any labor.
IRC R105.2 exempts a deck of 200 sq ft or less that stays under 30 in above grade, is not attached to the dwelling and does not serve the required exit door.
IRC R403.1.4 requires deck footings to bear at least 12 in below undisturbed grade and below the local frost line, whichever is deeper.
AWC DCA 6 requires deck guard posts of at least 4x4 nominal and a hold-down anchor rated for 1,800 lb of tension at a 36 in guard height.
Guard is the line item that swings a deck budget most: wood typically runs $25 to $50 per linear foot installed in 2026 and stainless cable $95 to $190.

Frequently asked questions

How much does it cost to build a 12x16 deck?

A 16 by 12 foot ground level deck in capped composite with a composite guard and four steps typically runs $7,800 to $15,700 installed, about $41 to $82 per square foot. The same deck in pressure treated pine with a wood guard lands near the bottom of that range.

Is composite decking worth the extra cost?

On a 192 sq ft deck the composite surface costs about $1,500 to $2,900 more than pressure treated up front. Cleaning and restaining that area six times over 15 years typically runs $2,900 to $5,800, so the upcharge pays back on maintenance alone.

Do I need a permit to build a deck?

IRC R105.2 exempts a deck only if it is 200 sq ft or less, stays under 30 inches above grade, is not attached to the house and does not serve the required exit door. Anything ledger-attached or elevated is permitted work, with a footing inspection before the concrete goes in.

Why is deck railing so expensive?

It is a structural assembly, not trim. Every post needs a 1,800 lb hold-down and two bolts into a 2x8 or deeper rim, and the top rail has to take a 200 lb push in any direction. Wood typically runs $25 to $50 per linear foot installed, composite $55 to $105 and stainless cable $95 to $190.

Sources and references

Cost to Build a Composite Deck (Trex)
DCA 6-2015 Prescriptive Residential Wood Deck Construction Guide (American Wood Council)
Chapter 5 Floors, Section R507 Decks, 2021 IRC (ICC)

Next steps for this project

The usual order for a framing, decks & fences project. See all framing, decks & fences calculators.

Results are estimates based on standard formulas and typical product specifications. Confirm quantities with your supplier and local code before ordering.