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Deck Construction Cost Estimator

Quantities from IRC R507.6, R507.5(1) and AWC DCA 6 Table 4

Most deck cost pages quote a national average with no source and no date. This one counts the actual materials your deck needs, then lets you price them at your own yard.

Deck cost estimate

ft
ft
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Quantities are sized against IRC Table R507.6, IRC Table R507.5(1) and AWC DCA 6 Table 4. Prices are pre-filled from a range another publisher printed, attributed and dated below. Change them to yours.

Specification summary

Generated from on . Reopen that address to reproduce these figures exactly.

Entered

Result

ledgerhousejoiststhe half the beam carries(tributary width)beampostpostpostjoist span, ledger to beambeam spanbeam spanThe span table asks for the full joist span, not the shaded half.
How beam span and joist span are measured

Price ranges

If you have no quote yet, the figures below give you something to enter.

Cost per square foot, as published by decks.com, cost to build a deck
ItemLowHigh
Pressure-treated wood$3$6
Cedar$4$8
Composite$5$14
Redwood$7$12
Bamboo$3$10
Ipe$10$20
Aluminum$15$20
Labor$8$22

Source: decks.com, cost to build a deck. Last price check: September 6, 2026. decks.com gives no source and no date for these figures and does not say which regions or which year they describe.

Lumber price trend

Nobody publishes a free, citable per-board retail price. What does exist is the Producer Price Index, softwood lumber from the US Bureau of Labor Statistics, series WPU0811, which is free, dated and revised on a schedule. It stood at 300.614 in July 2026. Softwood lumber is +15.0% against July 2025, so a price published much before then is likely low.

Source: US Bureau of Labor Statistics series WPU0811, read 2026-09-07. An index is not a price: it tracks what producers charge, not what your yard charges, so use it to judge the direction of travel rather than to set a figure.

Deck pressure washing prices

As each row states
ItemLowHighUnit
Deck pressure washing, typical job$100$250total
Per sq ft$0.30$0.35per sq ft
Handyperson or washing service$50$100per hour
Staining, added$850$850average
Sealing, added$900$900average

Source: HomeAdvisor, how much does it cost to pressure wash a deck. Last price check: September 13, 2026.

The source's typical job tops out at $250, while its own per sq ft rate prices a 1,000 sq ft deck at $350.

Worked example

A 12 ft by 16 ft deck in Douglas fir-larch, joists at 16 in centers, priced at a yard quoting $2.40 a foot for decking.

  1. The frame is sized first. IRC Table R507.6 gives the joist that spans 12 ft at 16 in centers, and R507.5(1) gives the beam. That decides how much timber there is before any price is applied.
  2. Footings follow the beam. The post spacing sets the Table 4 row, which gives the footing diameter, and the diameter and your depth give the concrete volume in bags.
  3. Then the quantities are counted. Joist linear feet, beam plies, decking rows and linear feet, screws at two per crossing, one hanger per joist.
  4. You supply the prices. Enter what your yard actually charges per foot and per bag. Leave a line blank and it stays a quantity rather than becoming a guess.
  5. The total is arithmetic. Quantity times your price, plus optional labor per square foot, divided by the area for a cost per square foot you can compare against a quote.

The value here is the quantity list, not the total. Two yards forty miles apart will price the same deck differently, and neither of them is the national average a cost article would have quoted you.

The formula

There is no cost formula, because there is no honest cost constant. What there is, is a takeoff multiplied by prices you supply:

cost = Σ (quantityn × your pricen) + area × your labor rate
quantity
counted from the code-sized frame, not estimated per square foot
your price
what your yard quotes, today, for that item
area
deck width times length, in square feet
No national average, no regional multiplier, no index. Those are the parts other cost pages invent.

Because the quantities are sized against the same tables as the rest of this site, changing species or spacing changes the bill of materials, not just a label. Wider joist spacing means fewer joists and fewer hangers, and a species change can move the joist size and the whole footing schedule.

Quantities from the code, prices from your yard

Prices move; quantities do not. Lumber moves week to week and varies by region, delivery and yard. The published ranges on this page are a starting point, and the price your supplier quotes is the one to enter.

What is defensible is the quantity. How many joists, how many linear feet of decking, how many bags of concrete: those follow from your dimensions and the code tables, and they do not change with the market. That part this site will stand behind.

So the split is deliberate. Quantities from the code, prices from your yard. Take the list to a supplier, or enter their numbers and let the page do the arithmetic.

What the estimate leaves out

The takeoff covers the structure and the deck surface: joists, beam, posts, footings, decking, screws and hangers. It does not include the ledger and its flashing and bolts, stairs and their stringers, guard posts and balusters, joist tape, post bases and caps, concrete tube forms, permit fees, excavation, or removing whatever is there now.

Those are real money on a real deck, and several of them are decisions rather than quantities. Add them from your own drawings rather than letting a page invent them.

Comparing this against a contractor's quote

The useful comparison is not the total, it is the per-square-foot figure and the material line items. A quote well above your priced takeoff is not automatically high: it carries labor, insurance, waste, hardware, permits and profit. But if the materials line in a quote is double the yard price for the same quantities, that is a question worth asking.

Print the sheet and take it with you. It lists the quantities and the code table each member was sized against, which is a firmer footing for a conversation than a number from a cost article.

Frequently asked questions

Why does this not just tell me what a deck costs?
Because nobody can, honestly. Lumber pricing is regional and moves weekly, so a published figure is stale almost immediately. What is stable is the quantity of material your deck needs, and that is what this page computes.
How much does a 12x16 deck cost?
That depends entirely on your lumber prices, and anyone quoting a single national figure is guessing. This page tells you exactly what a 12 ft by 16 ft deck needs in joists, beam, posts, footings, decking and fasteners. Price those at your yard for a real answer.
Does it include labor?
Only if you enter a labor rate per square foot. There is no default, because labor rates vary more than materials do.
Are the quantities the same as the deck materials calculator?
Yes. Both read the same code tables through the same build-time data, and a build-time check compares them across 75 deck configurations.
Should I add waste?
Yes. The takeoff is exact, with no allowance. Most builders add 5 to 10 percent on decking, and more where there are mitres or a picture-frame border.
Why is the frame sized before the price?
Because the frame decides the quantity. You cannot count joists until you know whether the span needs a 2x8 or a 2x10, and that comes out of IRC Table R507.6, not out of a price list.
What does a 12x12 or 20x20 deck cost?
The two rates this page pre-fills scale with area. At the decks.com figures quoted below, $3 to $6 per square foot for pressure-treated decking and $8 to $22 for labor, a 12x12 deck of 144 square feet is $432 to $864 of decking and $1,152 to $3,168 of labor. A 20x20 deck of 400 square feet is $1,200 to $2,400 and $3,200 to $8,800. Joists, beam, posts and footings are priced separately in the takeoff.
What does a wooden deck cost compared with composite?
decks.com lists decking at $3 to $6 per square foot for pressure-treated wood, $4 to $8 for cedar, $7 to $12 for redwood and $10 to $20 for ipe, against $5 to $14 for composite. The frame this page sizes is lumber in every case, so changing the deck surface changes the decking line and leaves the joist, beam and footing quantities where they are.
How much does it cost to power wash a backyard deck?
HomeAdvisor gives $100 to $250 for a typical deck pressure washing job, or $0.30 to $0.35 per square foot, and $50 to $100 per hour for a handyperson or washing service. At the per square foot rate the 192 square foot worked example is $58 to $67, below the source's own typical job. Staining adds $850 on average and sealing $900.
What does a 10x10, 10x12 or 12x20 deck cost?
An approximate cost comes from the two per square foot rates this page pre-fills. At decks.com's $3 to $6 for pressure-treated decking and $8 to $22 for labor, a 10x10 deck of 100 square feet is $300 to $600 of decking and $800 to $2,200 of labor. A 10x12 of 120 square feet is $360 to $720 and $960 to $2,640, and a 12x20 of 240 square feet is $720 to $1,440 and $1,920 to $5,280. The frame and footings are priced separately in the takeoff.
What does a deck rebuild or resurfacing cost?
Resurfacing keeps the frame and replaces the deck boards, so the decking line is the one that applies: decks.com gives $3 to $6 per square foot for pressure-treated wood and $5 to $14 for composite, plus $8 to $22 for labor. A full rebuild is a new deck and is estimated like one here. Demolition of the old deck, the demo line on a quote, is not in the takeoff and neither source on this page prices it.
What is the most cost effective decking material?
On decks.com's figures, pressure-treated wood at $3 to $6 per square foot has the lowest top end of the types listed. Bamboo starts at the same $3 but reaches $10, and aluminum at $15 to $20 is the most expensive. Labor at $8 to $22 is one line whichever wood or material you choose, and at these rates it is larger than the pressure-treated decking line.
How much does it cost to restain a deck?
HomeAdvisor's deck pressure washing guide gives staining at $850 on average as an addition to the wash, and sealing at $900. The wash itself is $100 to $250 for a typical job. The rows quoted here include no figure to repaint a deck.
How much does it cost to power wash a deck?
HomeAdvisor's June 2026 guide gives $100 to $250 for a typical job and $0.30 to $0.35 per square foot, with staining afterwards averaging $850.
How much does a wooden deck cost?
HomeAdvisor's June 2026 guide gives $10 to $20 per square foot for a ground-level deck, with pressure-treated wood at $2 to $5 and cedar at $3 to $7 per square foot for the material alone.
How much does a 10x20, 8x10 or 16x16 deck cost?
HomeAdvisor's June 2026 guide gives $10 to $20 per square foot for a ground-level deck. At that rate an 8 by 10 ft deck is $800 to $1,600, a 10 by 20 ft deck $2,000 to $4,000 and a 16 by 16 ft deck $2,560 to $5,120. A floating deck is $20 to $60 per square foot.
How much does it cost to build a deck yourself?
Building it yourself removes the labor. HomeAdvisor's June 2026 guide gives $15 to $35 per square foot for deck labor, and material per square foot of $2 to $5 for pressure-treated wood, $3 to $7 for cedar and $12 to $22 for composite. The lumber calculator counts what to buy.

Check these numbers yourself

How every figure here is verified: Sources & Method. Who builds this: , and the method is on About. Found something wrong? Tell us and it gets fixed or removed.

Figures on this page last checked against the source documents on 2026-09-06. Codes are amended locally; confirm against the edition your jurisdiction enforces.

Related calculators

Estimates only. Quantities are a takeoff from prescriptive code tables for a rectangular ledger-attached deck, with no waste allowance and no ledger, stairs, guard, hardware, permit or site-work costs included. Prices are whatever you enter; this site publishes none. Confirm quantities against your own drawings and prices against your supplier before you buy.