Job Profit Margin Calculator
Reviewed by Gerald G., founder & reviewing editor of CalcAuthority — journeyman cabinet installer, former subcontractor, and former contracting business owner who operated with 18 employees. The framing is from the field; every number comes from the stated formula.
The job is done, the customer paid, the truck moved on — but did the job make money? Most contractors answer with a feeling. This calculator answers with arithmetic: contract price minus burdened labor, materials, subs, and the job's share of overhead, expressed both in dollars and as a margin. Run it on every closed job and your estimating improves automatically, because you finally see which kinds of work earn and which quietly drain. Companion tools: Bid Check for before the job, this one for after — and the Markup vs. Margin guide for why the percentage is computed on price, not cost.
How It Works
Two layers matter and they answer different questions. Gross margin (price minus direct job costs, over price) tells you whether the work itself was priced above what it consumed — labor at burdened rates, materials, subs, rentals. Net job margin then subtracts the job's share of company overhead. A job can show a comfortable gross margin and still be a net loser once it pays its share of the office, trucks, insurance, and your salary — which is precisely how a busy year ends in a flat bank account.
Use actual, final numbers: real hours worked (including the punch list and the callback trip), real material invoices, real change-order revenue. The gap between this result and what the Bid Check projected at bid time is your estimating error, itemized.
Worked Examples
Example 1 — solid job. Contract price $20,000. Burdened labor $7,500, materials $5,000, subs and other $1,500 → direct costs $14,000. Gross profit = $6,000 (30% gross margin). Overhead at 10% of price = $2,000. Net job profit = $4,000 — a 20% net margin. This job paid its way and funded the company.
Example 2 — the job that felt fine. Price $8,500. Labor $4,200, materials $2,600, other $400 → direct costs $7,200. Gross profit = $1,300 (15.3%). Overhead at 10% = $850. Net job profit = $450 — a 5.3% margin. One extra half-day of labor (~$500 burdened) would have pushed it negative. Nothing about this job felt like a problem while it was running.
What This Result Means
Net job margin is the fraction of the customer's money the business actually kept after the job paid for itself and its share of existence. Across a year, your average net job margin times your revenue is roughly your operating profit — so a book of 5% jobs means one bad job erases twenty good ones' cushion. The dollars column matters just as much: margins compare jobs; dollars pay bills.
Reading the Result
- Negative net margin: the job cost you money to perform. Find the cause — estimate, execution, or scope creep — before taking another like it.
- 0–8%: fragile; ordinary friction eats jobs like this. A book full of them is the underbidding trap.
- 8–15%: workable, sustainable if consistent.
- Above 15%: healthy — identify what made this job good and bid for more of it.
Bands are editorial reading aids, not industry statistics — sustainable margins differ by trade, region, and risk. Your own job history, run through this calculator, is the benchmark that matters.
When to Use This Calculator
Use this calculator:
- At every job close-out — ten minutes with final numbers, filed where you can compare jobs.
- When choosing what work to chase — sort your last twenty jobs by net margin and the business tells you what it wants more of.
- When a customer type or job type keeps "feeling" unprofitable — replace the feeling with the number.
- Before repeating a similar bid — last time's actual margin is the best single input to next time's price.
Limitations
- Accuracy depends on cost capture: unlogged hours, shop material grabs, and warranty trips all hide in the margin if untracked.
- Overhead as a flat percentage of price is a simplification of true allocation.
- Single-job view: it does not show portfolio effects like a loss-leader that feeds profitable repeat work — judge that consciously, not by default.
- Pre-tax operating result; not your personal take-home.
Frequently Asked Questions
Should callbacks count against the job's margin?
Yes — warranty hours and materials are real costs caused by the job, and assigning them back is what makes the margin honest. If you track callbacks separately, run the Callback Cost Calculator for the company-wide picture, but still charge each callback's cost to the job that generated it. A job is not closed until its warranty tail is counted.
What is the difference between this and the Bid Check Calculator?
Same math, different moment. Bid Check runs on estimates before you quote — it projects. This runs on actuals after the job closes — it records. The most valuable number is the difference between the two on the same job: that gap, tracked across jobs, is a map of exactly where your estimating runs hot or cold.
My gross margin is fine but net keeps coming out thin. What does that mean?
Your jobs are priced above their direct costs but the company's overhead is consuming the difference. Either overhead is too high for your revenue (check it with the Overhead Recovery Calculator) or your pricing formula is not actually recovering the overhead percentage you think it is — commonly caused by using markup-on-cost arithmetic. The Markup vs. Margin guide shows the fix.