Job numbers
Result
- Current gross margin --
- Max total spend at target --
- Remaining budget at target --
Enter the contract value, what you have spent so far, and your target margin. This calculator returns actual gross margin, remaining budget, and an on-track or over-budget verdict for the job.
Built by a Tampa Bay pool project manager for small crews who need a real answer, not a Gantt chart.
Start with the signed contract value. If a change order has already been executed and added to contract, include it. If it is still floating in email, leave it out for now and re-run once it is signed.
Cost to date is direct job cost only. Include burdened labor (wages plus payroll tax plus workers comp plus benefits, roughly 1.25 to 1.40 times raw wages for most trades), materials, sub balances paid, and direct equipment or fuel tied to this job. Do not include general overhead (office rent, insurance across the business, truck payments across all jobs, phone bills, marketing). Overhead gets counted against your monthly profit-and-loss, not per-job cost. Fold it in and you distort what the job actually earned.
Target gross margin defaults to 40 percent. That is a common working number for Florida pool renovation and residential remodel. If you run a service-heavy trade with tight competition, dial that down to 30 or 32. If you run high-touch custom work, bump it to 45 or 50. Whatever you enter, the calculator uses it to compute the maximum total job cost you can absorb and still hit the target.
The optional Estimated remaining costs field is the one that flips the tool from a snapshot into a forecast. Add up what you still owe subs, what materials are still on order, and the labor hours left times your burdened rate. Punch it in. The calculator adds it to cost to date, computes the projected finish margin, and tells you either you are on track or you are over budget by a specific dollar amount.
Hit Calculate. Everything runs in your browser. Nothing you type leaves your device.
Gross margin per job is the single most important number a small-crew contractor tracks. Not revenue. Not backlog. Not job count. Margin. Because the revenue and the backlog and the job count all lie about what the business actually makes, and margin does not.
Here is a real example from a Wesley Chapel pool renovation I ran in 2024. Signed contract was $46,000. My target gross margin was 38 percent. That means my maximum direct job cost was $46,000 times 0.62, or $28,520. Two weeks in, cost to date was $18,400. Remaining costs looked like $12,000 (plaster crew balance, tile, equipment install labor). Projected total cost was $30,400. That is $1,880 over the $28,520 ceiling. On paper the job was still profitable, just at 34 percent margin instead of 38, but I only saw the problem because I was tracking these two numbers in the same place. Without that check, I would have found out at close-out that the job made $4,000 less than my quote assumed. Multiply that miss across four jobs a quarter and it is a payroll.
The formula the calculator runs on is straightforward. Current gross margin is (contract minus cost to date) divided by contract, times 100. Maximum total spend at target is contract times (1 minus target as decimal). Remaining budget is max spend minus cost to date. Projected margin, if you supply remaining costs, is (contract minus cost to date minus remaining) divided by contract, times 100. The verdict is the sign of (max spend minus cost to date minus remaining). Positive means on track. Negative means over budget by that dollar amount.
What this calculator does not do: it does not track the number over time, alert you when actual cost crosses target, or fold in overhead so you see a net margin. For that you need software with a live job header showing contract, spent, and margin every day. Which brings up the reason most enterprise construction tools charge $349 to $499 a month for the ability to run a Gantt chart but bury the profit view under 40 menus. That is The Bloatware Tax at work.
The Bloatware Tax is the percentage of a SaaS bill spent on features the customer never touches. For small-crew contractors on enterprise PM software (Buildertrend at $499 a month, JobTread at $349, Procore at $500 plus per user), that number usually runs 60 to 80 percent. Ask a five-person crew when they last opened a submittal workflow, an AIA G702, a resource-leveling view, or a critical-path Gantt. Most of them can't remember. They open estimates, invoices, chat, time tracking, and the job header. That's it.
I ran this out on a Bayshore Boulevard pool build in Tampa in 2024. The company had a $349 a month PM tool and could not tell me the actual gross margin on a live job without opening a report builder and picking three dimensions. Meanwhile the office was double-entering costs into QuickBooks anyway because the sync did not carry job-level detail. The tool solved zero of the problems the crew actually had and cost more than the phone bill. I built Workhand on that job.
A profit margin calculator that runs in a browser tab is not the answer to that problem. It is a spot check. The answer is a tool that shows you contract, spent, and margin every time you open the job. That is what live per-job profit tracking should look like on a phone in the field.
Workhand does per-job profit tracking automatically. The job header shows contract, spent, and gross margin every time you open it. When a job crosses your target, the margin badge flips color and the crew sees it before the office does. Free plan for one active job, no credit card.
See how per-job profit tracking works or Get Workhand free
Related reading: How to calculate profit per job and How to price a pool renovation in 2026.
Built and operated by Andrew Bernardo, project manager at a Tampa Bay pool builder, at Innovative Ops LLC in Wesley Chapel, Florida.