Free tool for contractors
Job cost calculator: is this job actually making money?
Before you sign the contract
Enter the bid price and your real costs — fully loaded labor, materials, subs, and an honest overhead allocation — and see the job's true margin. Then look at the profit-fade line: what a 10% cost overrun does to your profit. No email required. Use it right here.
Founder, Accelerate Business Solutions · Published August 21, 2026 · Last updated August 21, 2026
Your numbers
The truth about this job
Healthy marginGross margin
34.9%
- Total job cost (incl. overhead)
- $55,328
- Gross profit
- $29,672
- Markup on cost
- 53.6%
- Break-even price
- $55,328
- Profit per labor hour
- $93
Profit fade check
If costs run just 10% over estimate, margin drops to 28.4% — that's $5,533 of profit gone. This is why jobs get tracked monthly, not at closeout.
How to use it well
Three rules that make this calculator honest.
Load your labor fully
A $28/hr tech costs $40–$45 with taxes, comp, and benefits. Use the real number or the margin is fiction.
Never skip overhead
Office, insurance, vehicles, admin — overhead is real even when it's not on the job site. 10–20% of direct costs is the typical range.
Recheck at 50% complete
Bid-time math is a guess. The same math with actuals at the halfway point is management. That's job costing.
The math behind it
How job cost is actually calculated.
Nothing here is complicated — which is why it's so often wrong. Job cost math breaks in two predictable places: labor priced at base wage instead of true cost, and overhead that never touches the job at all. Both make thin jobs look healthy.
Total job cost
labor (hours × fully loaded rate) + materials + subs + equipment + other direct costs + allocated overhead
Overhead allocation is the line most owners skip. Your truck, insurance, shop, and office are real costs of doing the job even though they never show up on the job site.
Gross profit
contract price − total job cost
Include approved change orders in the contract price. Unbilled change orders are the quietest form of revenue leak in the trades.
Gross margin
gross profit ÷ contract price
The number to judge a job by. Above 20% is healthy for most trades, 10–20% is thin, under 10% has no room for a single surprise.
Markup on cost
gross profit ÷ total job cost
Not the same as margin, and the confusion is expensive. A 20% markup is a 16.7% margin — bid enough work on that mix-up and it compounds into a real hole.
Break-even price
total job cost
The number below which you're paying to work. Worth knowing before you 'sharpen the pencil' on a bid.
Doing this once per bid by hand works. Doing it on every job, every month, from real transactions is what job costing in QuickBooks is for — and getting labor into it correctly is covered in how to job cost payroll in QuickBooks.
Questions contractors ask about job margins
What overhead percentage should I use?
Divide your annual overhead (office, insurance, vehicles, admin salaries, software — everything that isn't a direct job cost) by your annual revenue. Most small trade companies land between 10% and 20%. If you've never calculated it, that's exactly the kind of number job costing surfaces.
What's a good gross margin for a contractor?
It varies by trade, but as a rule of thumb: above 20% is healthy, 10–20% is thin and needs watching, and under 10% leaves no room for a single surprise. Many owners who think they're at 25% discover they're at 12% once labor is fully loaded and overhead is allocated.
Should labor be fully loaded?
Yes. Use the true hourly cost: wages plus payroll taxes, workers' comp, benefits, and non-billable time. A $28/hour tech often costs $40–$45 fully loaded. Under-loaded labor is the most common reason 'profitable' jobs aren't.
How do I calculate job cost? What's the formula?
Total job cost = direct labor (hours × fully loaded rate) + materials + subcontractors + equipment and rentals + other direct costs, plus an allocated share of overhead. Gross profit is contract price minus that total; gross margin is gross profit ÷ contract price. Markup is a different number — gross profit ÷ total cost — and confusing the two is how contractors accidentally bid at half the margin they intended.
What's the difference between margin and markup?
Margin is profit as a percentage of the price you charge. Markup is profit as a percentage of what the job cost you. A 20% markup is only a 16.7% margin. If you've been marking up 15% and calling it a 15% margin, you're roughly 2 points thinner than you think on every job — the calculator above shows both so the gap is visible.
What is profit fade and why does the calculator show it?
Profit fade is margin that erodes between the bid and the closeout — overtime, rework, extra trips, un-billed change orders. The 10% overrun line shows what a fairly ordinary overrun does to this job's profit. On thin jobs it usually wipes out most of it, which is the argument for reviewing estimate vs. actual monthly instead of at closeout.
Can I use this calculator for a QuickBooks job costing setup?
It's a good sanity check before or alongside one. This calculator prices a single job by hand; QuickBooks job costing does the same math continuously on every job from your actual transactions. If your QuickBooks per-job report and this calculator disagree, the usual culprits are un-loaded labor rates or overhead that never touches job math — see the QuickBooks job costing guide.
Is the calculator free? Do you store my numbers?
Free, and no. Everything runs in your browser — there's no email gate, no account, and nothing you type is sent anywhere or saved.
Keep going:
- Job costing in QuickBooks: a contractor's guide — the five-step setup that tracks this on every job, automatically.
- The WIP schedule, explained — see every job's margin and billing position in one monthly report.
- How to job cost payroll in QuickBooks — building the fully loaded labor rate this calculator depends on.
- Does QuickBooks Pro have job costing? — which QuickBooks version can actually track this for you.
- Bookkeeping & job costing for contractors — how we run this for trade businesses every month.
Want this tracked on every job, every month?
This calculator is one job, once. Job costing is every job, every month — estimate vs. actual, flagged while there's time to fix it. Book a free 30-minute consult and we'll show you what it looks like on your books.
Book your free consult