Deck Cost Calculator
What a timber or composite deck costs from its size and material, installed or DIY, with elevation, steps, balustrade and a contingency — and the low-to-high range for the material.
Area × the rate per square metre for the material and price band (installed, or DIY materials only) gives the decking cost; an elevated deck is multiplied by the elevation factor.
| Decking | $8,000.00 |
|---|---|
| Contingency | $800.00 |
How the deck cost calculator works
Area × the rate per square metre for the material and price band (installed, or DIY materials only) gives the decking cost; an elevated deck is multiplied by the elevation factor. Steps and balustrade are added at their unit costs, then the contingency percentage on the subtotal. Every figure is rounded to the nearest $10, as an estimate should be.
Formula: Decking = area × rate × (elevated ? factor : 1) · subtotal = decking + steps + balustrade · total = subtotal × (1 + contingency%)
How the deck cost is worked out
Area × $/m² by material and basis, then the extras
The calculator takes your deck's area (length × width) and multiplies it by a per-square-metre rate for the material and basis you pick — supplied-and-installed or DIY materials only — at a low, typical or high price band. It then applies an elevation multiplier if the deck is over about a metre off the ground, adds any steps and balustrade, and finishes with a contingency buffer. Because deck pricing genuinely varies with the site, frame and finish, it also shows a low-to-high range rather than pretending there's one exact number.
Worked example
A 20 m² merbau deck at ground level, supplied and installed at the typical rate of about $400/m², is roughly $8,000 for the deck surface. Add a 10% contingency and you're near $8,800 — before any steps, a balustrade or an elevated frame. Swap to treated pine (~$250/m²) and the same deck is about $5,000; step up to premium composite (~$650/m²) and it's about $13,000.
Decking materials & ratesDecking materials and what they cost
Typical supplied-and-installed rates by material (2026 market-survey ranges — approximate):
- Treated pine — ~$250/m² (about $180–$350). Cheapest to build; needs oiling or staining every year or two.
- Merbau / hardwood — ~$400/m² (about $300–$550). The popular middle ground — rich colour, hard-wearing, still needs oiling.
- Spotted gum — ~$470/m² (about $350–$600). A premium Australian hardwood with a dense, tight grain.
- Composite, mid-range — ~$420/m² (about $280–$550). Capped, hollow-core boards; no oiling, just a wash.
- Composite, premium — ~$650/m² (about $500–$900). Solid-core, best look and feel; dearest to build, near-zero upkeep.
The trade-off is price vs upkeep vs looks. Treated pine wins on upfront price but costs the most to maintain. Hardwoods like merbau and spotted gum look the best and wear well, but need oiling to hold their colour. Composite costs the most to build yet never needs oiling — you're paying upfront to buy back a decade of weekends. There's no single "best" board; it depends on your budget, how long you'll keep the deck, and how much maintenance you're willing to do.
DIY, elevation, steps & getting a real quoteDIY, elevation, steps and getting a real quote
Building it yourself
Labour is roughly half a deck's installed price, so DIY materials only cost about half the installed figure. On a 20 m² treated-pine deck that's around $5,000 installed versus about $1,600 in materials — a saving near $3,400. Real money, but a deck needs footings, a level frame, correct bearer and joist spans and often a council permit, so budget your time and skill honestly and check what's allowed before you start.
Elevation, steps and balustrade
A deck more than about a metre off the ground costs roughly 30–50% more — taller posts, deeper footings, bracing, a balustrade by law and sometimes engineering. Steps run about $150–$400 each, and a balustrade is roughly $120–$350 per metre (timber-and-wire around $180/m, glass around $320/m). These add up fast, so set them at the Detailed precision level for a realistic total.
Getting an accurate quote
This tool is a planning ballpark. For a real number, get at least three itemised quotes for the same scope (size, material, steps, balustrade, height), and check each one includes footings, the subframe, fixings, waste removal and any permit, and whether it's supplied-and-installed or labour-only. A big spread between quotes usually means the builders have priced different scopes.
Frequently asked Frequently asked questions
Where these figures come from
The cost here is built from your deck's size and a per-square-metre rate — there is no single official price for a deck, because it depends heavily on the material, the frame, the site and the finish. The rates below are 2026 market-survey ranges drawn from typical Australian builder and supplier pricing; they are approximate and design-dependent, not a quote.
- Installed rates (typical) — treated pine ~$250/m², merbau ~$400/m², spotted gum ~$470/m², mid composite ~$420/m², premium composite ~$650/m². Each has a wide low-to-high band because sites and finishes vary.
- DIY materials — roughly half the installed rate, since labour is about half the job. You still supply the footings, subframe timber, boards and fixings.
- Add-ons — elevated decks add about 30–50%; steps run $150–$400 each; balustrade $120–$350 per metre depending on style (timber-and-wire vs glass).
- Upkeep — timber decks need oiling or staining every one to two years; composite needs only an occasional wash.
- Further guidance — ACCC — consumer rights on quotes, contracts and guarantees.
Last checked: July 2026. All prices are indicative market ranges and vary by region, material, site and design. This is a planning estimate — always get at least three itemised quotes for the same scope before you commit.
Understanding your resultSelect the question that matches where you are right now.
The headline number is the estimated cost of your deck: the deck surface (area × rate for your material and basis) plus any elevation uplift, steps, balustrade and a contingency buffer. The range underneath shows how much that can move as pricing swings from budget to premium.
What to do with itUse it to set a budget and sanity-check the quotes you get. If a quote lands well outside the range, ask what's different — the material, the frame, the site or the scope.
What it is notIt's not a fixed quote or a structural design. It doesn't size footings, bearer and joist spans, or bushfire/cyclone requirements — those come from your builder, engineer or council.
Why a rangeDeck pricing genuinely varies. The same deck can differ 30–50% on site conditions, access, height and finish alone, which is why the tool shows a low-to-high band rather than one number.
Four things move a deck's cost the most: the size, the material, whether it's installed or DIY, and the height and add-ons.
Material choiceThe board is the biggest single lever on the rate — pine at ~$250/m² versus premium composite at ~$650/m² is more than double. Pick for how long you'll keep the deck and how much upkeep you'll do.
Installed vs DIYLabour is about half the installed price. Doing it yourself can nearly halve materials cost, but you take on footings, a level frame and a possible permit.
Height, steps and balustradeAn elevated frame adds 30–50%; steps are $150–$400 each; a balustrade is $120–$350 per metre. A ground-level deck with no rail is the cheapest build — every metre up and every add-on lifts the total.
A few habits keep the estimate honest and the quotes comparable.
Measure the real footprintUse the actual deck length and width, and set the height and add-ons at the Detailed level. A deck that looks small on paper grows once you add steps and a rail.
Quote like for likeGet three itemised quotes for the same scope and material. Check each includes footings, subframe, fixings, waste removal and any permit before you compare the totals.
Think ten years, not oneA cheap timber build can cost more to own once you count oiling every year or two. Weigh the upfront saving against a decade of upkeep before choosing the board.
A deck is usually one line in a bigger outdoor or renovation budget. Model the rest of the job and the money side too.
Tiling nearbyWorking out tiles for a patio, path or the area around the deck?
Tile calculator → Pouring footings or a slabNeed concrete for footings, a landing or a slab under the deck?
Concrete slab calculator → Financing the projectCheck what you could borrow before committing to a bigger build.
Borrowing capacity → Related calculators 🧱Concrete SlabFootings & slabs 🧩Tile CalculatorTiles, boxes & cost 🧾Cost of LivingHousehold running costs 🏠Mortgage RepaymentFinance a reno 🔑First Home BuyerBuying to renovate 📊Borrowing CapacityHow much you can borrow 🧮Renovation BudgetPlan a renovation budget 🌱TurfHow many rolls of turf you You might also be interested in 🧱Concrete SlabFootings & slabs 🧩Tile CalculatorFinish the area 🧾Cost of LivingBudget the whole home 🏠Mortgage RepaymentWhat a reno loan costs 📊Borrowing CapacityBefore you commit 🔑First Home BuyerBuying a doer-upper Rate this calculatorQuick answers
A 20 m² merbau deck, installed About $8,000 (decking only)
At the typical supplied-and-installed rate of around $400/m², a 20 m² merbau deck at ground level is about $8,000 for the deck surface. Add a 10% contingency and you're near $8,800. Merbau is the most popular Australian hardwood decking — rich colour, hard-wearing, and it needs oiling every year or two to hold its look.
| Area × rate | 20 m² × $400/m² |
|---|---|
| Decking | ≈$8,000 |
| With 10% buffer | ≈$8,800 |
| Range | $6,000–$11,000 surface |
- Upkeep Oil every 1–2 years
- Add-ons Steps, balustrade, elevation extra
A 30 m² composite deck, installed About $12,600 (mid-range)
Mid-range composite (capped, hollow-core) runs around $420/m² installed, so a 30 m² deck is roughly $12,600 for the surface. Composite costs more upfront than pine but never needs oiling or staining — you trade a higher build cost for near-zero maintenance. Premium solid-core boards push $650/m² and beyond.
| Area × rate | 30 m² × $420/m² |
|---|---|
| Mid composite | ≈$12,600 |
| Premium composite | $500–$900/m² |
| Maintenance | No oiling ever |
- vs pine ~1.7× the build cost
- Payoff No re-oiling over its life
Which decking material — and what it costs $250–$650/m² installed
Installed rates by material (typical): treated pine ~$250/m² (cheapest, most upkeep), merbau/hardwood ~$400, spotted gum ~$470 (premium hardwood), mid composite ~$420, premium composite ~$650. On a 25 m² deck that's roughly: pine $6,250, merbau $10,000, spotted gum $11,750, composite $10,500. Pine wins on price; composite wins on maintenance; hardwood wins on looks.
| Treated pine | ≈$250/m² |
|---|---|
| Merbau | ≈$400/m² |
| Spotted gum | ≈$470/m² |
| Composite (mid) | ≈$420/m² |
- On 25 m² $6,250 to $11,750
- Cheapest life-cost Depends on how long you'll keep it
DIY vs paying a builder Save ~$3,400 on a 20 m² pine deck
Labour is roughly half a deck's installed price. A 20 m² treated-pine deck is about $5,000 installed but only ~$1,600 in DIY materials (boards, subframe timber, fixings) — a saving near $3,400 if you build it yourself. That's real money, but a deck involves footings, bearer/joist spans, a level frame and often a council permit; budget your time and check what's allowed before you start.
| Installed (20 m² pine) | ≈$5,000 |
|---|---|
| DIY materials | ≈$1,600 |
| Saving | ≈$3,400 |
| Trade-off | Your time + skill + permit |
- Hard bits Footings, frame, levels
- Check first Council / permit rules
Why an elevated deck costs more Add roughly 30–50%
A deck more than about a metre off the ground needs taller posts, deeper footings, bracing, often a balustrade by law, and sometimes engineering — so it costs around 30–50% more than the same deck at ground level. A 20 m² merbau deck at $8,000 on the ground becomes roughly $11,200 elevated (×1.4). Very high or cyclone-rated decks can exceed $1,000/m².
| Uplift | +30–50% |
|---|---|
| 20 m² merbau ground | ≈$8,000 |
| Same, elevated | ≈$11,200 (×1.4) |
- Why Posts, footings, bracing, rails
- May need Engineering + permit
Steps, balustrades & the extras They add up fast
The deck surface is only part of the job. Steps run about $150–$400 each, and a balustrade or handrail is roughly $120–$350 per metre (timber-and-wire ~$180, glass ~$320). A 20 m² merbau deck with 3 steps and 6 m of balustrade goes from $8,000 to about $10,235 before contingency. Add these at the Detailed precision level for a realistic total.
| Steps | $150–$400 each |
|---|---|
| Balustrade | $120–$350/m |
| 20 m² + 3 steps + 6 m rail | ≈$10,235 |
- Glass balustrade Dearest (~$320/m)
- Set them Detailed precision level
The real cost is over 10 years Cheap to build ≠ cheap to own
Timber decks need oiling or staining every 1–2 years — call it $200–$500 in materials and a weekend each time, or $30–$50/m² if you pay someone. Over 10 years that maintenance can rival the gap to composite, which needs only an occasional wash. When comparing pine or hardwood against composite, weigh the upfront saving against a decade of upkeep before you decide.
| Timber upkeep | Oil every 1–2 yrs |
|---|---|
| Composite upkeep | Wash occasionally |
| 10-yr view | Upkeep can close the gap |
- Pine Cheapest build, most upkeep
- Composite Dearest build, least upkeep
Getting an accurate quote Three quotes, same scope
This tool gives a planning ballpark — a real quote depends on your ground (sloping or elevated costs more), the subframe, access, and finish. Get at least three itemised quotes for the SAME scope (size, material, steps, balustrade), check they include footings, subframe, fixings, waste removal and any permit, and confirm whether it's supplied-and-installed or labour-only. A big spread between quotes usually means they've priced different scopes.
| Get | 3 itemised quotes |
|---|---|
| Same scope | Size, material, add-ons |
| Check included | Footings, permit, removal |
- Big spread? Different scopes priced
- This tool A planning ballpark, not a quote
Worked examples
| Inputs | Estimated deck cost | Note |
|---|---|---|
| 5 m × 4 m merbau, installed, typical price | $8,800 | $8,800 with a 10% contingency |
| DIY treated pine at the low band | $1,100 | $1,100 |
| An elevated composite deck at the high band | $20,330 | $20,330 |
FAQFrequently asked questions
How much does a deck cost in Australia?
As a rough guide, a supplied-and-installed deck runs about $250/m² for treated pine, $400/m² for merbau, $470/m² for spotted gum, and $420–$650/m² for composite. So a 20 m² deck at ground level is roughly $5,000 in pine or $8,000 in merbau before steps, a balustrade or elevation. These are 2026 market-survey ranges that vary with your site and finish — always get itemised quotes.
What's the cheapest decking material?
Treated pine is the cheapest to build, about $180–$350/m² installed (typically around $250). That's less than half the cost of premium composite, but pine needs oiling or staining every year or two, so it's the dearest to keep looking good. Merbau and other hardwoods sit in the middle on both price and upkeep.
Is composite decking worth the extra cost?
Composite costs more upfront — about $280–$550/m² for mid-range and $500–$900/m² for premium, versus roughly $250/m² for pine — but it never needs oiling or staining, just an occasional wash. Over ten years the maintenance saving can close much of that gap, so it often pays off if you'll keep the deck a long time and don't want the upkeep.
How much can I save building it myself?
Labour is roughly half a deck's installed price, so DIY materials cost about half the installed figure. On a 20 m² treated-pine deck that's around $5,000 installed versus about $1,600 in materials — a saving near $3,400. But a deck needs footings, a level frame, correct bearer and joist spans and often a council permit, so budget your time and check what's allowed before you start.
Why does an elevated deck cost more?
A deck more than about a metre off the ground needs taller posts, deeper footings, bracing, a balustrade by law and sometimes engineering, so it typically costs 30–50% more than the same deck at ground level. This calculator applies an uplift multiplier — about ×1.4 by default — when you set the deck to elevated.
Do these prices include steps and a balustrade?
The per-m² rate covers the deck surface — the boards plus the subframe. Steps and balustrades are separate: budget about $150–$400 per step and $120–$350 per metre of balustrade (timber-and-wire around $180/m, glass around $320/m). Add them at the Detailed precision level for a realistic total. Sources
The sources behind this calculator
- American Association of Feline Practitioners — Feline Life Stage Guidelines — the six feline life stages the cat-age page uses
- Wang et al. 2020, Cell Systems — Quantitative translation of dog-to-human aging by conserved remodeling of the DNA methylome — the 16·ln(age)+31 epigenetic formula on the dog-age page
- Fair Work Ombudsman — sets hospitality award wages — why tipping is optional in Australia
Last checked: July 2026. Where a page states a convention (a tipping custom, a pet life stage), the page names the body it follows.