Decking · live calculator
Decking m² to dollars in 4 minutes.
Length × width in. Board profile, joist spacing, fixing type picked. The engine calculates board count with 7% offcut buffer, joist linear metres, fixings per m², sealant coverage, and your labour at AUD/m².
Prepared for
47 Riverside Cres, Earlwood 2206
- Merbau decking 38m² (boards)$2,470
- Joists + bearers (linear m)$680
- Fixings + sealant$340
- Labour · 16h$1,600
- GST (10%)$509
inc 10% GST
Already in the template
The maths your Excel sheet keeps getting wrong.
Everything below is baked into the decking template before you sign up. You answer your business questions once in onboarding, every quote rebases.
- 01
Board count from m² × profile width with 7% offcut buffer (industry standard)
- 02
Joist linear metres scaled by spacing (450mm / 600mm) and span direction
- 03
Fixings per m² (clip rate × board count) — Spax / Camo / face-fix
- 04
Sealant coverage at 8m²/L for two coats
- 05
Labour per m² — your rate from onboarding, not generic averages
Why tradies switch
Faster quotes, the same maths every time.
Stop second-guessing offcuts
7% offcut buffer is conservative enough that you don't need to drive back to Bunnings, tight enough you don't bid yourself out of the job.
Joist maths the customer accepts
Itemised joist linear metres on the PDF stops the 'why is the deck $X but the boards are only $Y?' conversation. The engine shows the working.
Add merbau / spotted gum / composite without re-doing the calc
Board profile is a dropdown. Switch between 86×19 merbau and 90×23 composite — the engine recalculates board count, fixings, and labour without you opening Excel.
Under the bonnet
How the engine handles the edge cases
Board count from m² isn't just area divided by board width. The engine factors the gap (typically 4mm for hardwoods, 6mm for composites), the offcut buffer, and the joist direction. If the joists run east-west and the boards run north-south on a 6x4m deck, the board count is different from a 4x6m deck with the same area. Most spreadsheets miss this. The template doesn't.
Joist linear metres aren't just (deck width / joist spacing). You also need the joists at the perimeter ends, the bearer-joist junctions, and the trimmer joists around any obstacles (posts, pool edges, planter boxes). The engine assumes a clean rectangle by default but lets you bump 'complexity' from 0 to 3 to add the extra trimmers. Most quotes are 0 or 1.
Sealant coverage assumes two coats at 8m² per litre per coat, which is the conservative end of every manufacturer's spec sheet. If you're using a heavier oil (Cabot's Aquadeck, for instance) the engine drops coverage to 6m²/L automatically when that product is the picked default. Means you don't go short on the second coat.
Decking · FAQ
Trade-specific questions.
The questions decking tradies actually ask. Want to see how it works on a real job?
Does the calculator handle stairs and screening?
Stairs are an add-on at a flat rate per riser (configurable). Screening or privacy slats are a separate area-based line item with their own m² rate. Both keep your itemised PDF clean.
What if my customer wants a particular board?
Add it once in Settings then Calculator defaults: profile width, length, supplier price per metre, your markup. From then on it's a dropdown choice on every new deck quote.
Can I quote a multi-level deck?
Yes. Quote each level as its own line item with its own m². The engine sums across levels and applies one labour rate. For complex multi-elevation decks, the AI photo extraction (Pro plan) reads from a sketch.
What's the offcut buffer set to? Can I change it?
7% by default, which matches the AS 1684 + Forest & Wood Products Australia guidance for residential decking. If you're working with a tight species (spotted gum, blackbutt) and want a 10% buffer, override it in Settings then Calculator defaults. Per-quote overrides also work for one-off jobs.
Does it handle joist + bearer separately?
Yes. Joists run perpendicular to the boards at the spacing you pick (450mm or 600mm). Bearers run perpendicular to the joists at 1800mm centres by default. The engine totals linear metres for both, separately, so the customer's PDF shows the substructure without you doing the maths.
What about hidden fixings vs face-fix?
Pick at the start of the quote. Hidden fixings (Spax, Camo, Tiger Claw) bump the fixings cost (~20% more per m²) and add 15% to labour because they're slower. Face-fix is the default. The engine handles both without you tracking the labour adjustment.
Can I quote merbau + composite on the same deck?
Yes. Add each species as its own line item with its own m². The engine treats them as separate substrates but pools the labour because crew time is crew time. Useful for two-tone decks or a composite border with a timber field.
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