How to Know Your Numbers as a Contractor (and Why I Had to Build the Software Myself)

He runs a construction company doing about $4.5 million a year, and he works harder at his numbers than almost any contractor I know. And 1 day he'd had it: "I'm submitting all the receipts. Why do I keep having to go back and add all this?" That question is why my software exists, and it explains what it means to know your numbers as a contractor: not tax paperwork, a working instrument panel for a business carrying real risk every day.

This is the story of why I stopped recommending other people's software and built my own, and the lesson inside is about what your business deserves to know about itself.

The stakes: owners punished for trying

I spent years running a 150-person retail operation across 7 states, $24 million a year. At that size you get an instrument panel: margin by department, cash position, cost reports that somebody answers for. As a bookkeeper for contractors, I watched owners carry the same risk with none of those instruments, and the software they bought would never give it to them.

A while back, a plumbing company hired us to set up job costing. They ran 1 of the big field platforms, and their expenses would not come over to QuickBooks. The workaround I designed, hand-sorting every expense in QuickBooks and reworking it in a spreadsheet each month, never launched: the owner looked at it, said it was too much, and he was right. The software made the job so heavy that a willing owner walked away from his own numbers.

So I went shopping on my clients' behalf: the big platforms, the receipt apps, all of it. At the time, nobody moved expenses into the books, and the receipt apps could not capture what job costing needs: which job, which category, and what part of the ticket is a job cost versus a company expense. I covered that gap in why contractor software can't tell you if you made money.

And then there is the contractor from the top of this story: $4.5 million a year, trying harder at job costing and business segmentation than anyone I worked with. Every month I sent him a list of questions: which job does this receipt belong to? Which job is this bill for? Until he finally said it: "Why do I keep having to answer all these questions? I don't have time for this." He was not wrong; the system was punishing the hardest-working guy in the room for trying.

The 3-instrument panel

Here is what those owners were missing and big companies have always had. 3 instruments matter most, and none is complicated math.

Instrument 1: your margin target (how to calculate overhead and profit)

Take what it costs to keep your doors open for a year, your overhead, and divide it by the revenue you expect. That is your overhead rate. Add the profit percent you refuse to skip, and you have the bar every single job has to clear.

Big companies grade every bid against that bar; most contractors have never been shown how to set it. The SBA's guide to managing your business finances covers the basics; we walk the full pricing math in how to price a job so you actually make money.

1 rule we hold at Best Decision Bookkeeping: never plan a job below 30% gross margin. A bid planned under that cannot cover overhead and leave profit, no matter how smoothly the job runs.

Instrument 2: margin by segment (contribution margin in plain English)

Which parts of your business actually earn? Accountants have a name for the dollars each part kicks in toward covering your overhead and profit: contribution margin. That is the whole concept; no degree required.

Big companies rank every division by it, feed the winners, and fix or fire the losers. You can do the same at your size, if, and only if, the field data reaches the books.

Instrument 3: job-level truth (estimate vs actual on every job)

Estimate next to actual on every job, while the job is still warm. This instrument fixes your pricing: the next bid is only as smart as the last job's real numbers. Job costing is the engine underneath: every receipt, hour, and bill tagged to its job when it happens.

The 1 missing ingredient (and why I built Best Decision Project Tools)

All 3 instruments die without 1 ingredient: the receipt, the hours, and the job tag making it from the truck to the books. That ingredient is exactly what the software market would not build. So I built it.

The first version of Best Decision Project Tools was exactly 1 feature: receipt capture with a voice memo. The guy in the truck photographs the receipt, says the job name out loud, and is done; the bookkeeper gets a clean screen to assign the job and category, even split 1 receipt across 3 jobs. That 1 feature ended the monthly question war with the $4.5 million contractor.

Then it grew, because every client conversation added a question: can it do this? Usually, by the next day, it could. Today it is about 155,000 lines of code, 97 database tables, 676 automated tests, and 12 AI features, built in under 5 months. It runs on a machine in my office, so the AI costs about $250 a month instead of a per-click cloud bill.

And 1 rule has never bent: I have never built a feature that weakens the financial core. A client once asked for a quick way to fire off an invoice; I will make converting an estimate into an invoice as fast as humanly possible, but I will not build a side door around the system that keeps job costs true. Fast is fine. Hollow is not.

1 honest thing: none of this works without you. The crew still says the job name into the phone; somebody still approves the receipt. No software can invent data your company did not capture; good software makes the capture cheap enough that it happens, and every instrument above turns on.

The fix: 3 things to do this week

1. Trace 1 receipt's full journey and find the 4 break points. Follow 1 receipt from the truck to your books: how do hours get from the crew to payroll? How does a receipt get its job name? Who types the same thing twice? Where would a profit-by-job report actually come from? Every break point is an instrument that is dark right now, and the list is your real software requirement, better than any feature comparison. (The IRS expects you to keep these records anyway; the job tag makes them useful before tax time.)
2. Set your margin target tonight. Annual overhead divided by expected revenue, plus the profit percent you refuse to skip. Write it where you build estimates: every bid clears the bar or it does not go out.
3. Grab the free Mini CFO Dashboard. It is the spreadsheet version of a CFO dashboard for small business owners: enter up to 3 segments, the revenue and direct costs for each, your overhead, and your profit target. It hands back margin by segment, each segment's contribution toward covering overhead, and your margin target bar. 10 minutes, and your instrument panel exists on paper.

A worked example: the margin target and the segment read

Margin target first, on our demo company, TC Summit General Contracting, a GC doing about $1.5 million a year. Overhead runs $25,000 a month, $300,000 a year; divided by $1,500,000 of expected revenue, that is a 20% overhead rate. Add the 10% profit the owner refuses to skip and the margin target is 30%. In Best Decision Project Tools, the CFO Dashboard grades every estimate against that bar the moment it is priced, and Segment Performance shows the 3 divisions side by side with the margin dollars each kicks in toward overhead, its contribution.

Now the segment read, using the generic example loaded in the Mini CFO Dashboard (example numbers, not industry data; replace them with yours). A contractor runs 3 segments in a month: Remodels at $45,000 revenue and $27,000 direct cost (40% margin, contributing $18,000), Service Work at $25,000 and $14,500 (42%, contributing $10,500), and New Construction at $30,000 and $21,900 (27% actual, contributing $8,100). Overhead is $22,000 a month and the profit target is 10%, so the margin target bar sits at 32%.

2 segments clear the bar; New Construction came back at 27% actual, the drag, visible in 1 row. To be clear, 27% is an actual result, never a number to plan (bids still get planned at 30% or higher). Spotting the segment that keeps landing under the bar is what this instrument is for.

FAQ: how to know your numbers as a contractor

What numbers should a contractor track?

Start with 3 instruments: a margin target (your overhead rate plus the profit percent you refuse to skip), margin by segment (which parts of the business actually earn), and estimate versus actual on every job while it runs. All 3 depend on 1 ingredient: receipts, hours, and job tags making it from the field to your books.

How do contractors calculate overhead and profit?

Add up what it costs to keep your doors open for a year (your overhead) and divide by the revenue you expect; that is your overhead rate. Add the profit percent you refuse to skip and you have your margin target. Example: $300,000 of overhead on $1,500,000 of revenue is 20%; add a 10% profit target and every bid has to clear 30%.

What is contribution margin in plain English?

Contribution margin is the dollars a part of your business kicks in toward covering your overhead and profit, after its direct costs are paid. Rank your segments by it and the decision reads itself: feed the winners, fix or fire the losers.

What is a good gross margin for a contractor?

Our rule at Best Decision Bookkeeping: never plan a job below 30% gross margin; under that, the job cannot cover overhead and leave profit. Plans between 30% and 35% are fragile; any overrun or scope surprise can push the job into a loss after overhead. For most trades, 35% to 45% planned gross margin is the healthy range.

How do I know if my construction business is making money?

Your tax return answers that once a year, months too late to act. To know in time, you need margin by segment and estimate versus actual while each job runs. A quick test: trace 1 receipt from the truck to your books and ask where a profit-by-job report would come from. If there is no answer, the data is dying before it reaches you.

Turn your instrument panel on

Start with the free Mini CFO Dashboard. 10 minutes with your real numbers and your instrument panel exists on paper; you will see your business the way I saw that contractor's.

Want the story on camera, with the instrument panel live? Watch the Week 9 episode of Behind the Books below.

If this story made you curious about Best Decision Project Tools, current pricing is on the Best Decision Project Tools pricing page. Or reach out and we will look at your numbers together.

Find us at BestDecisionBookkeeping.com and BestDecisionBusiness.com.

About Best Decision Bookkeeping

Best Decision Bookkeeping helps contractors get answers out of their books, not just tax returns: job costing, segment profitability, and pricing from real job history. Before founding the firm, Joe ran a 150-person retail operation across 7 states doing $24 million a year. The firm also builds Best Decision Project Tools, which captures job costs in the field and feeds the books clean. Learn more at BestDecisionBookkeeping.com and BestDecisionBusiness.com.