Stop Losing Money: Job Costing for Tradespeople

The Problem No One Talks About

Ask any tradesperson how their last job went, and you'll hear: "Yeah, went grand." Ask them how much profit they actually made, and you'll get a pause, a shrug, and something like "enough, I'd say."

Here's the uncomfortable truth: most tradespeople don't know their true profit on any given job. They know what they quoted. They know roughly what they spent on materials. But the real costs — all of them — rarely get tracked.

And that's how good tradespeople with full diaries end up wondering where the money goes.

The Numbers Don't Lie

Research from the UK Federation of Master Builders found that nearly 40% of small trade businesses operate on net margins below 5%. That means on a €10,000 job, after all costs, the business keeps less than €500.

Some are even running at a loss without realising it — the cash keeps flowing, so it feels like things are fine. But cash flow isn't profit. And one quiet month or one bad debt can expose just how thin the margins really are.

Hidden Costs That Eat Your Profits

When you quote a job, you probably think about materials and your time. But there's a long list of costs that quietly chip away at your profit:

1. Return Trips

You quoted a day for the job. It took a day and a half because of an issue with the existing pipework. That extra half-day isn't just lost time — it's lost revenue from the job you could have been doing.

Typical cost: €150–300 per return trip (your time + fuel)

2. Untracked Materials

You grabbed a few fittings from the van that you'd bought weeks ago. You didn't add them to this job's costs because you couldn't remember exactly what they cost. Over a month, these "forgotten" materials add up to hundreds of euros.

Typical cost: €50–150 per job in untracked small items

3. Fuel and Travel

How much does it cost you to get to site each day? If you're driving 30km each way in a van, that's roughly €12–15 per day in fuel alone, plus wear and tear.

Typical cost: €50–75 per week per job (if not factored into the quote)

4. Waste and Surplus Materials

You bought 10% extra materials "just in case." That's good practice — running short is worse. But if you're not returning or reusing the surplus, it's a cost.

Typical cost: 5–10% of your materials bill

5. Admin Time

The time you spent writing the quote, ordering materials, coordinating with the customer, sending the invoice, and chasing payment. None of this is billable, but it's all real work.

Typical cost: 1–2 hours per job at your hourly rate

6. Callbacks and Snags

Even on a well-done job, customers sometimes call back. A leaking joint, a blown fuse, a crack in the grout. If you're going back for free to fix snags, that's a real cost.

Typical cost: €100–200 per callback

7. Tool Wear and Replacement

Your tools don't last forever. Every job wears them down a little. If you're spending €2,000–5,000 per year on tools and equipment, that's €40–100 per week that needs to be covered by your jobs.

Add It All Up

On a job quoted at €3,000:

| Item | Amount | |------|--------| | Materials (quoted) | €900 | | Untracked materials | €75 | | Extra half-day (overrun) | €200 | | Fuel and travel | €60 | | Admin time (2 hours) | €80 | | Tool wear allocation | €30 | | Total actual costs | €1,345 | | Quoted price | €3,000 | | Apparent profit | €1,655 | | Real profit | €1,655 |

Wait — that doesn't look too bad, right? But we haven't deducted your overheads yet: van payment (€350/month), insurance (€200/month), phone (€50/month), software (€30/month), accountant (€100/month), safety gear, training, certifications...

If your monthly overheads are €1,500 and you do 8 jobs per month, each job needs to cover €187.50 in overheads.

Real profit after overheads: €1,467.50

Now divide that by the 3.5 days the job actually took: €419 per day before tax.

Is that enough? Only you can answer that. But the point is: you can't answer it at all if you're not tracking the numbers.

What Is Job Costing?

Job costing is simply tracking all costs against each individual job, so you know the true profit for every piece of work you do.

It means recording:

Materials — everything used on the job, at your actual cost
Labour — your hours (and any employees or subcontractors)
Direct expenses — skip hire, equipment rental, specialist tools
Overhead allocation — a share of your fixed business costs

When the job is complete and paid, you can see exactly how much you made (or lost).

How to Start Job Costing (Even If You've Never Done It)

Step 1: Track Your Materials Per Job

Every time you buy materials, assign them to a job. Every time you use stock from the van, note it. This doesn't need to be complicated — a photo of the receipt tagged to the job number is a start.

Step 2: Track Your Time Per Job

At minimum, note the days (or hours) spent on each job. Include travel time. Include callbacks. Be honest — the numbers are for you, not the customer.

Step 3: Record Direct Expenses

Skip hire? Scaffolding rental? A subcontractor for the day? These go against the job.

Step 4: Know Your Overhead Rate

Add up all your fixed monthly costs:

| Overhead | Monthly Cost | |----------|-------------| | Van (payment + tax + NCT) | €400 | | Insurance (van + public liability + employer) | €250 | | Phone and broadband | €60 | | Software and subscriptions | €50 | | Accountant | €100 | | Tools and equipment (amortised) | €150 | | Workwear and PPE | €30 | | Miscellaneous | €60 | | Total monthly overheads | €1,100 |

If you work 20 billable days per month, your overhead rate is €55 per day. Add this to every job.

Step 5: Review After Every Job

When a job is done, pull up the numbers:

What did you quote?
What did you actually spend (materials + labour + expenses + overheads)?
What was the profit?
What was the profit margin?

If a job made 30%+ margin, brilliant. If it made 5%, you need to understand why — and fix it for next time.

A Real Job Costing Example

The Job: Full Bathroom Renovation

Quoted price: €8,500 (materials included)

| Cost Category | Estimated | Actual | |--------------|-----------|--------| | Materials | €2,500 | €2,850 | | Labour (you, 6 days × €350) | €2,100 | €2,450 (7 days — tiling took longer) | | Subcontractor (tiler, quoted €800) | €800 | €800 | | Skip hire | €250 | €300 (needed a second uplift) | | Fuel/travel (6 days × €15) | €90 | €105 | | Overhead allocation (6 days × €55) | €330 | €385 | | Total costs | €6,070 | €6,890 | | Profit | €2,430 | €1,610 | | Margin | 28.6% | 18.9% |

Without job costing, you'd think you made €2,430. In reality, you made €1,610 — a difference of €820. Over a year of similar jobs, that's €10,000+ in phantom profit you thought you had but didn't.

What Job Costing Tells You

Once you've tracked costs on 10–20 jobs, patterns emerge:

Which job types are most profitable — you might discover that boiler installs make 35% margin but bathroom renovations only make 15%
Where time overruns happen — if tiling always takes a day longer than quoted, adjust your quotes
Which suppliers give the best value — compare material costs across jobs
Whether your pricing is right — if most jobs come in under 20% margin, your prices are too low
Where to focus your business — more of the profitable work, less of the marginal stuff

How TradeTime Makes Job Costing Easy

Job costing sounds like a lot of admin. And if you're doing it on spreadsheets, it is. That's why TradeTime builds job costing into the flow of work:

Log materials against jobs — snap receipts, pull from your price list, or enter manually
Track time automatically — clock in and out of jobs from your phone
Record expenses — assign costs to jobs in seconds
See live profit margins — before the job is even finished, you know where you stand
Compare quoted vs actual — on every job, across all jobs, by job type
Spot trends — dashboards show which work is making you money and which isn't

You don't need to be an accountant. You just need to use the tools.

Key Takeaways

Most tradespeople don't know their true profit per job — and it's costing them thousands per year
Hidden costs are everywhere — untracked materials, overruns, travel, admin, and callbacks
Job costing = tracking all costs against each job — materials, labour, expenses, and overheads
Start simple — track materials and time per job, know your overhead rate
Review every job — the gap between estimated and actual profit is where you learn
Use software — manual job costing is possible but painful. Automation makes it sustainable.

Know Your Numbers. Grow Your Business.

Try TradeTime free — built for Irish & UK tradespeople. Automatic job costing, live profit margins, and quoted-vs-actual tracking on every job. Stop guessing — start knowing.