Fencing & decking
Deck Estimate Calculator
Builds a deck quote, where the two things that break estimates are the ground and what is under the old decking.
Result
A planning estimate, not a quote. Access, the age of the equipment, what is found once it is opened up and local labour rates all move the real figure, sometimes a long way.
Get a Free Business AuditHow the calculation works
Hours times crew times rate, plus materials and the call-out, then tax. As an estimating tool the discipline is separating what you can see from what you cannot. Deck area, decking material and railing length are measurable and can be priced confidently. Footing digging conditions and the state of an existing frame are not, and both are capable of moving a quote substantially. The workable approach is to price the known scope firmly and state the unknowns as named variations with a rate, rather than padding or absorbing them.
What moves the number
- Ground conditions for footings, which are unknown until digging starts.
- On a rebuild, the condition of the existing frame and ledger under the old boards.
- Material waste, since decking cut to length and pattern generates offcuts.
- Permit and inspection timing, which affects the schedule rather than the price.
Where this one goes wrong
On a rebuild, assume the frame needs attention until you have seen it. Old decking hides rotten joists, a ledger fixed with nails, and missing or absent flashing, and a quote that covered only replacing boards becomes a difficult conversation when the deck cannot safely be redecked as it stands. Say in the quote that the frame will be inspected once boards are up and that repairs are a variation. The ledger in particular has to be brought up to standard rather than reused if it was never correctly fixed, because redecking a deck hanging on nails leaves a collapse risk under a new surface.
Before you quote
- State frame inspection and repair as a named variation on any rebuild.
- Check the ledger fixing and flashing before quoting a redeck.
- Include realistic waste for the decking pattern chosen.
Where the rules come from
Questions
About this calculator
Why can a deck rebuild quote change once work starts?
Because the old boards hide the frame. Rotten joists, a ledger fixed with nails instead of bolts, and missing flashing are all common and none are visible until the decking is up. A quote that only covered new boards has to change if the structure underneath is not sound.
Can I just replace the decking and keep the frame?
Only if the frame and the ledger connection are sound. Putting a new surface on a deck that is inadequately attached to the house leaves a collapse risk hidden under new boards. Checking the ledger fixing and the joists first is what determines whether a redeck is possible.
How much waste should a deck estimate carry?
Enough for the cutting the pattern requires, which is modest on a simple rectangle and considerably more with mitres, picture framing or diagonal boards. Composite is expensive enough that getting the waste allowance right matters more than with treated timber.
The formula
total = hours x people x rate + parts + call-out, then sales tax
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How to use this calculator
- Hours on site (h). Enter your own figure; the page starts at 20 h.
- People needed. Enter your own figure; the page starts at 1.
- Labour rate charged ($). Enter your own figure; the page starts at $78.
- Parts and materials ($). Enter your own figure; the page starts at $2,000.
- Call-out or diagnostic fee ($). Enter your own figure; the page starts at $95.
- Sales tax (%). Leave at zero if you are quoting before tax.
The result updates as you type, so you can try a figure, see what it does to estimated total, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Hours on site | 20 h |
| People needed | 1 |
| Labour rate charged | $78 |
| Parts and materials | $2,000 |
| Call-out or diagnostic fee | $95 |
| Sales tax | 0% |
What comes out
| Result | Value |
|---|---|
| Estimated total main result | $3,655 |
| Labour | $1,560 |
| Before tax | $3,655 |
| Sales tax | $0 |
About $3,655: $1,560 of labour, $2,000 of parts and a $95 call-out.
How sensitive the answer is
Holding everything else steady and changing only labour rate charged, this is what happens to estimated total. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Labour rate charged ($) | Estimated total |
|---|---|
| $39 | $2,875 |
| $59 | $3,275 |
| $78 example above | $3,655 |
| $117 | $4,435 |
| $156 | $5,215 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Hours on site (h)
- Measured in h, between 0 and 400, starting at 20 h.
- People needed
- A number, between 0 and 40, starting at 1.
- Labour rate charged ($)
- A money amount, starting at $78.
- Parts and materials ($)
- A money amount, starting at $2,000.
- Call-out or diagnostic fee ($)
- A money amount, starting at $95.
- Sales tax (%)
- Leave at zero if you are quoting before tax.
What the results tell you
| Result | What it is |
|---|---|
| Estimated total | The headline result. A money figure. |
| Labour | A money figure. |
| Before tax | A money figure. |
| Sales tax | A money figure. |
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.