The invisible profit leak most contractors never see
Here's the scenario. The job is done, the client is happy, the invoice is paid. It feels like a win. But if you sat down and added up what the job actually cost — every hour, every material run, the fuel, the time spent going back for a part you didn't quote — the margin would be a lot thinner than the number you sent on the quote.
Most contractors never do that calculation. Not because they're lazy, but because there's no easy way to do it. You quote the job, you do the job, you get paid, you move on. The feedback loop is broken.
The result: you can be busy, booked three weeks out, invoicing steadily — and still not making what you should be. The jobs feel profitable because cash is coming in. But revenue and profit are not the same thing, and in the trade business, the gap between them is where most contractors quietly bleed money.
Research consistently shows that small contracting businesses operate on tighter margins than owners realise. A 2023 survey of trade contractors found that more than 60% could not state their average job margin within 10 percentage points. They knew their hourly rate. They knew their materials markup. But the actual margin on a completed job? No idea.
That's the invisible profit leak. Not one big loss — a hundred small ones, spread across every job, that no one ever adds up.
Quoted margin vs real margin: why they're never the same
Every quote has an implied margin built into it. You add up materials, you add labour at your rate, you add a buffer, and the difference between that and the invoice total is what you expect to make.
But that quoted margin is a fiction. It's based on what you think the job will cost, not what it actually does.
The real margin is only knowable after the job is complete: when you know the actual hours worked, the actual materials spent, and every other cost that landed on the job. And the real margin is almost always lower than the quoted margin — because the quoted version assumes everything goes to plan.
Jobs that run over on hours by even two hours on a $1,200 quote can swing from 35% margin to 20%. Jobs where you forgot to quote a permit fee, or had to make an extra material run, or spent 45 minutes on site troubleshooting something that wasn't in scope — each of those erodes the margin without anyone noticing in the moment.
A healthy trade job runs 35–50% gross margin. That's the benchmark. Below 20% and you're likely working for little more than your direct costs once you factor in business overhead — insurance, vehicle, tools, slow months. Below 10%, you're probably losing money in real terms.
The problem is that without a system for comparing quoted margin to real margin on every job, you have no idea where you sit. You're flying blind. Every quote is a guess anchored to the last guess, and the errors compound quietly over time.
The four places jobs lose money
There are four consistent culprits. Most jobs that underperform hit at least two of them.
1. Materials overruns
You quoted based on what you thought the job needed. The job needed more. Maybe you had to add a run to the supplier. Maybe a measurement was off. Maybe the scope crept slightly and you added materials without adjusting the invoice. The extra $80 in cable or fittings seems small in the moment, but across 50 jobs a year, $80 per job is $4,000 in unrecovered cost.
The fix is simple in principle: compare actual materials spend to what you quoted for materials, on every job. Not in aggregate — per job. Aggregate numbers hide where the problem actually is.
2. Labour creep
You quoted six hours. It took eight. The extra two hours feel like part of doing the job — you weren't going to leave it half-finished — so you absorb them without a second thought.
Labour creep is the most expensive and most invisible of the four. At $85/hour, two extra hours is $170 off the margin on a single job. If this happens on half your jobs, you're giving away thousands of dollars a year in unrealised labour.
This isn't about charging for every minute. It's about understanding which job types consistently run over on labour so you can quote them more accurately — or have a conversation with the client about scope before you're already two hours in.
3. Forgotten costs
Permit fees. Dump fees. The subcontractor you called in for one part of the job. Fuel for the extra site visit. These costs are real. They landed on the job. But they often don't make it onto the quote, and sometimes not even onto the invoice.
Forgotten costs are common because they happen at the edges of jobs — before the work starts, after it finishes, in the middle when something unexpected comes up. They're easy to miss because they don't fit neatly into the line items you quoted.
The discipline here is including an "other costs" line in your job actuals — a catch-all for anything that landed on the job that wasn't a material or a labour hour. Even a rough figure is better than nothing.
4. Underpricing
Some jobs are underpriced before they start. You quoted low to win the work, or you haven't raised your labour rate since costs went up, or you're matching a competitor who may be losing money too.
Underpricing is the hardest to fix because it's invisible until you measure it. If you've never compared real margin to quoted margin across all your job types, you don't know which types you're consistently underpricing. You just know some jobs feel harder than others.
With actual job data, the pattern becomes obvious: these job types consistently run below 20% margin. These clients consistently come in over on labour. This service has not been repriced in 18 months and the margin has collapsed. Now you can do something about it.
How to actually track job profit
The mechanics are simple. After every job, you need three numbers:
- What you invoiced — the revenue for the job.
- What you spent on materials — actual receipts, not your quote estimate.
- How many hours it actually took — multiplied by your true cost per hour.
From those three numbers you can calculate gross profit and margin for every job. You can compare it to what you quoted. You can start to see patterns.
If you want to work through the calculation manually, use the free Job Profit Margin Calculator — enter your invoice total, materials cost, and labour hours to see gross profit, margin %, and markup % instantly. It also covers the distinction between margin and markup, which trips up a lot of contractors.
The calculation itself isn't complex. The hard part is building the habit of doing it after every job — before the details fade, before you move on to the next one. Most contractors who start tracking actuals are surprised by what they find. Not because the numbers are catastrophic, but because the patterns are so consistent once you can see them.
Certain job types almost always run over on labour. Certain clients consistently have scope creep. Certain services haven't been repriced in years. None of this is visible from the invoicing side alone — you need the actuals to close the loop.
Why this matters more than landing more jobs
The instinct when revenue feels thin is to get more work. More quotes, more marketing, more jobs. And sometimes that's right. But if each job is running at 22% margin instead of 35%, getting more jobs just scales the problem. You're working harder for the same thin return.
The math is stark. A contractor doing $400,000 a year in revenue at 22% gross margin makes $88,000 gross profit before overhead. The same contractor at 35% margin makes $140,000 — a difference of $52,000 — without working a single additional hour or quoting a single additional job.
That $52,000 difference doesn't come from growth. It comes from understanding where jobs lose money and fixing it. From repricing the job types that are consistently thin. From quoting labour more accurately on the jobs that always run long. From recovering costs that are currently being absorbed silently.
This is why job costing is the highest-leverage thing most contractors aren't doing. It's not bookkeeping — it's intelligence. It tells you which clients are worth taking, which job types actually pay, and where your pricing needs to change before you quote the next one.
The contractors who build durable businesses aren't necessarily the ones who are busiest or best at marketing. They're the ones who know, after every job, whether they made money on it — and by how much.
Fieldpaid's Job Profit Reveal does this automatically. After a job is done, log your actual hours and materials in 60 seconds. When the invoice clears, you see real margin vs your quoted margin — on every job, without a spreadsheet. Free during beta for QuickBooks-connected contractors.