Contractor Estimate Builder
Turn a list of line items into a client-facing estimate with overhead, contingency and tax applied in order, and a total that adds up when the client checks it.
Estimate
Output
How it works
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List the work, one line at a time
Each line is a name, a vertical bar, and an amount — Labor | 1200. One number per line. Amounts can include a dollar sign or commas. A line that is not in that shape is listed in a warning above the estimate, so nothing is lost without you knowing.
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Set overhead, contingency and tax
These are applied in sequence rather than side by side. Overhead is a percentage of the line items; contingency is a percentage of the items plus overhead; tax is a percentage of all three. Each one compounds on what came before it.
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Hand over the total
Out comes an estimate a client can read and question line by line, with the three additions shown as their own figures rather than buried in the rates.
Who this is for
Bidding for work
An itemised estimate is much harder to haggle down than a single number, because a client arguing with it has to name which line is wrong.
Handling variations
When scope changes, change one line and rebuild rather than reconstructing the whole quote from memory.
Comparing subcontractors
Same line items, different suppliers, side by side — which is the only way to see whether a cheaper bid is cheaper or just less complete.
Explaining the price
Most price objections are really requests to understand the price. A breakdown answers the question that was actually being asked.
Questions
- What markup should I use?
- It depends on trade, risk and how much of the job is your own labour. The point of separating it as its own line is that you can see what happens when you move it, instead of burying it in the rates.
- Why is the contingency larger than my percentage of the subtotal?
- Because it is calculated on the subtotal plus overhead, not on the subtotal alone. Tax then applies on top of all three. The order is deliberate — it is how the additions actually stack — but it means the percentages compound rather than simply adding up.
- Why is one of my line items missing?
- Every line needs a name, a vertical bar and an amount, and the amount can include a dollar sign or commas. Any line that does not fit is listed in the warning above the estimate instead of being dropped, and a dash instead of a bar is the usual cause.
- Is an estimate binding?
- That depends on your jurisdiction and on what the document says. If you mean it to be an estimate rather than a fixed quote, say so on the document in those words.
- Should I show my markup to the client?
- Most contractors show a total and a breakdown of the work, not their internal margin. Untick Show overhead and contingency as separate lines and each line item is shown with its share already included, so the lines still add up exactly to the total. Leave it ticked when you want the client to see how the price is built.
- How large should the contingency be?
- Large enough to cover what you cannot see yet, which means it should vary with the job. Renovation on an old building warrants far more than new work on a clear site, and a single habitual percentage applied to both is wrong in one direction or the other.