Job Costing 101: Do You Know If Your Jobs Are Actually Profitable?
The busiest tradespeople are not always the most profitable ones. In fact, some of the most stressed and financially squeezed trades businesses in Ireland are extremely busy, taking on job after job, barely stopping, and wondering why the bank account doesn’t reflect all that effort.
The answer, almost always, is job profitability. They’re winning plenty of work. They’re just not winning the right work, at the right price, tracked properly enough to know the difference.
Job costing is how you fix that.
What job costing actually means
Job costing means tracking the real cost of each job separately (labour, materials, subcontractors, any direct costs) and comparing it to what you charged. The result is your actual margin on that job.
It sounds obvious. Surprisingly few trades businesses do it systematically.
Most tradespeople have a general sense of whether a job went well or badly. But “that felt like a good one” is very different from knowing you made a 22% margin. And “that one was a nightmare” is different from knowing you made 4%, or lost money outright.
Without job costing, you can’t identify which types of work are most profitable. You can’t see whether your labour estimates are consistently off. You can’t spot a customer whose jobs always run over and are never actually worth the hassle. You’re managing by feeling rather than information.
The components of a job’s real cost
A complete job cost has several elements, and the ones people leave out are usually the ones that kill the margin.
Direct labour. Hours worked multiplied by your loaded labour rate (not just what you pay yourself or an employee, but your loaded rate includes PRSI, holiday pay, and the overhead allocation per hour). See our guide to pricing for how to calculate your loaded rate.
Materials. The actual cost, not the estimate. Including delivery charges, any wastage, and materials you bought but didn’t use that can’t easily be returned.
Subcontractors. If you brought in another tradesperson for any part of the job, that cost belongs in the job cost.
Direct expenses. Skips, equipment hire, permit fees, anything you paid specifically for this job.
Travel time. This one gets ignored constantly. If you drove 45 minutes to a job and 45 minutes back, that’s 1.5 hours of your time that has a cost. On a small job, travel time can wipe out the margin entirely.
Rework. If you went back to fix something, whether your fault or not, that time cost belongs in the job.
A worked example: kitchen refit
Let’s say you quoted a kitchen fit-out at €3,800 all-in.
Here’s the actual job cost when tracked properly:
- Labour: 4 days × 8 hours = 32 hours × €42/hour (loaded rate) = €1,344
- Materials: quoted €1,100, actual spend €1,280 (extra tiles, one damaged unit replaced)
- Skip hire: €180
- Travel: 3 hours total across 4 days × €42 = €126
- Rework: 2 hours fixing a corner issue = €84
Total real cost: €3,014
Revenue: €3,800
Gross profit: €786, a margin of 20.7%.
That’s a reasonable result. But notice what would have happened if you hadn’t tracked the extra materials (€180 over), the travel time (€126), and the rework (€84). Those three items alone are €390 that you’d never see. Without tracking, this job looks like a 30%+ margin. With tracking, it’s 21%.
Now imagine that pattern across 40 jobs a year.
The jobs that look profitable but aren’t
There’s a category of work that most experienced tradespeople recognise intuitively but rarely measure: the jobs that feel busy and feel like they should make money, but somehow never do.
They tend to have certain patterns. The customer always has additional requests. Getting access or decisions from them takes more time than the work itself. The job is further away than typical. There are always snagging items that bring you back.
Job costing makes these patterns visible in numbers rather than feelings. When you see that a particular customer’s jobs consistently come in at 8% margin while your average is 19%, the decision to decline future work from them becomes much easier. You’re not being difficult. You’re being a businessperson.
How to track job costs without becoming an accountant
The good news is that you don’t need complex spreadsheets. Job management tools like Tradify and ServiceM8 both have built-in job costing features that let you log time and expenses against specific jobs as you go.
The discipline is logging as you go rather than trying to reconstruct it afterwards. Ten minutes at the end of each day logging time and materials is far more accurate than trying to remember a week later.
At the end of each job, you should be able to pull a simple report showing revenue, costs, and margin. Tradify vs ServiceM8, our comparison guide, covers how each handles job costing.
If you’re not yet on a job management system, a simple spreadsheet with columns for job reference, revenue, labour hours, labour cost, materials, other costs, and margin is enough to start building the picture.
What to do with the information once you have it
After three months of tracking, you’ll have enough data to draw some useful conclusions.
Which job types consistently make the best margins? Do more of those, quote them more confidently, and market specifically in that area.
Which job types consistently disappoint? Either reprice them to reflect the actual cost, or decline them in future.
Where are your estimates most often wrong? If you consistently underestimate materials on certain job types, build that in. If travel is always higher than you factor in, price it in.
The goal is not to achieve perfect margins on every job. That’s not realistic. The goal is to make consistently informed decisions rather than consistently surprising ones.
Want to understand your job profitability?
Job costing gives you the information. Acting on it is where the value comes. Our Fractional CFO for Trades service includes monthly analysis of your job margins, helping you identify where you’re making money and where you’re not.
Book a free 30-minute call. We’ll give you a straight picture of where you stand.
Or read next: Tradify vs ServiceM8: Which Job Management App Is Right for Your Trades Business?