In short
Track four things against every job: materials, your own hours at a rate you would pay someone else, anyone you paid, and mileage. Set the total against what you billed. In the worked example below, a $1,200 job nets $103, because the third parts run and the half day of help were never counted.
In this guide
Most tradespeople can tell you what they charged for a job. Far fewer can tell you what that job actually cost them, and whether it made money once the materials, the fuel, the extra hour on site, and the parts run were all counted. Job costing is how you close that gap.
What Job Costing Means
Job costing is the practice of tracking every cost that belongs to a single job, then setting those costs against the price you charged for that same job. The result is the one number that tells you whether the work was worth doing: profit per job.
That is different from looking at your bank balance at the end of the month. A healthy balance can hide a job that lost money, because a good job the week before covered for it. Job costing pulls the two apart so you can see each job on its own.
Every term on the right is a real cost you can point at. The discipline of job costing is simply making sure none of them go missing.
Why It Matters More for a Solo Trade
A large firm has an accountant, a costing system, and enough jobs that the averages smooth out. A sole proprietor has none of that, and every job is a bigger share of the year. If two jobs a month quietly lose money, that is a serious dent in your income, and without job costing you will not spot it until your accounts are done, long after you have quoted ten more jobs the same way.
Job costing gives you three things a bank balance never will:
- Honest quotes. Once you know what similar jobs really cost, you stop guessing and start pricing from evidence.
- Early warning. A job trending over budget shows up while you can still do something about it, not at year end.
- A record for the IRS. Every tracked cost is a categorized, receipted expense, which is exactly what your Schedule C needs.
Job Costing vs Estimating
This is the distinction most tools get wrong, so it is worth being clear. An estimate is a prediction you make before the job: what you think it will cost and what you will charge. Job costing is the reckoning after: what it actually cost.
Almost every "job costing" app on the market is really an estimating tool. It helps you build a quote, then stops. It never goes back to check whether the quote held up. That check, comparing estimate to actual, is where the money is, because it is the only way your next quote gets better than your last.
An estimate tells you what a job should cost. Job costing tells you what it did cost. You need both, but only one of them improves with every job you do.
What Counts as a Job Cost
Five buckets cover almost everything a trade job consumes. Track these and you have real job costing.
| Cost type | Examples | Where it hides |
|---|---|---|
| Materials | Cable, copper, fittings, boards, consumables | The second and third parts run you forgot |
| Labor | Your hours, at a rate that pays you properly | Unpaid "quick" return visits |
| Subcontractors | A helper for a day, a specialist, hired help | Cash payments with no receipt |
| Mileage | Trips to the supply house, to site, back again | Never logged, so never claimed |
| Job overhead | A share of insurance, tools, phone, van | Treated as "just business cost", never allocated |
The first four are direct: they belong to one job and one job only. Overhead is shared across all your jobs, so you allocate a slice of it. A simple way is to take your monthly fixed costs, divide by the number of jobs you typically do in a month, and add that figure to each job. It does not have to be perfect to be useful.
Your Labor Is a Real Cost
The single most common job costing mistake among sole proprietors is leaving their own time out. If you only count materials and cash paid to others, every job looks profitable, because you are working for free in the math.
Put a number on your hour. Whatever you would have to pay someone to do your work, that is the floor. Then count your hours on each job at that rate. Suddenly a job that "made $400 on materials" but ate two full days looks very different, and correctly so.
A Worked Example: A $1,200 Job
Take a residential job you quoted at $1,200.
| Billed | $1,200 |
|---|---|
| Materials, three parts runs | $430 |
| Your labor, 14 hours at $35 | $490 |
| Helper, half a day | $90 |
| Mileage, 60 miles at the standard rate | $27 |
| Job overhead allocation | $60 |
| Profit | $103 |
That is 9 percent. It is also a job most people would remember as a good earner, because $1,200 feels healthy and the $430 of materials was the only cost they watched. Job costing shows the truth: it was tight, and the third parts run and the half day of help were what thinned it. Next time, you quote with that in mind.
You can run your own numbers in seconds with the free job profit calculator.
How to Do Job Costing Without a Spreadsheet
The traditional answer is a spreadsheet: a tab per job, rows for each cost, formulas at the bottom. It works, and plenty of tradespeople run their business on one. But it has two failure points. First, it only holds what you remember to type in, and the parts run you forgot at 7am on a Tuesday never makes it. Second, it lives on a laptop at home, not in the van where the costs actually happen.
The receipt-first method fixes both. Every cost on a trade job comes with a receipt: the supply house slip, the fuel receipt, the invoice from your sub. If you capture the receipt at the moment you get it and tag it to the job, the job costing does itself. Nothing to remember, nothing to type up later. We cover the method in detail in how to track job costs from receipts.
This is exactly what VanReceipts is built to do: send the estimate and invoice from the same job, scan a receipt on the job (cloud AI reads the total and every line item, and you confirm), log mileage, tag costs to the job, and watch profit update on the spot.
Job Costing by Trade
The principle is the same for every trade, but the costs that catch people out differ. We have plain-English guides for the trades where the details matter most:
- Job costing for electricians: wire and conduit, testing time, and the part return runs nobody logs.
- Job costing for plumbers: fittings by the dozen, water heater parts, emergency service calls.
- Job costing for HVAC techs: equipment cost, refrigerant, install versus service work.
- Job costing for general contractors: subs, allowances, and the change orders that decide the margin.
- Job costing for painters: paint by coverage, prep materials, and the extra coat.
- Job costing for roofers: materials by the square, tear-off disposal, and hidden decking.
- Job costing for carpenters: lumber waste, hardware, and unbilled shop time.
- Job costing for landscapers: bulk material by the yard, equipment fuel, and plant replacements.
If you currently keep your books in QuickBooks and wonder why per-job profit is so hard to see, read why QuickBooks falls short on job costing for solo contractors.
Two numbers decide whether a job can make money before it starts: your real labor cost and the margin you price for. The labor cost calculator works out the first, and markup vs margin explains the second. When the job is done, how to write an invoice covers billing it.
What did that job really make?Profit and margin for any job in seconds.FAQ
What is job costing in simple terms?
Job costing is tracking everything one job costs you, materials, your labor, any help, mileage, and a share of overhead, then subtracting that total from what you charged. What is left is the profit on that job.
What is the difference between job costing and estimating?
Estimating happens before the job and predicts the cost. Job costing happens after and records the actual cost. Comparing the two is how your future estimates get more accurate.
Do I need accounting software to do job costing?
No. A spreadsheet works, and a receipt-scanning app that tags each cost to a job works better because it captures costs as they happen. You only need something that keeps every cost attached to the right job.
Should I count my own labor as a job cost?
Yes. Leaving out your own time is the most common reason a job looks profitable when it was not. Set an hourly rate for yourself and count your hours on every job at that rate.
How do I allocate overhead to a single job?
Add up your monthly fixed costs, insurance, phone, tools, van, then divide by how many jobs you usually do in a month. Add that slice to each job. It does not need to be exact to be useful.
Where to Start
You do not need to cost every job you have ever done. Start with the next one. Capture every receipt, put a rate on your hours, and at the end add it up. The first time you see real profit per job instead of a guess, you will not want to quote any other way.
Download VanReceipts on the App Store and cost your next job while you are still on the job.
