How to Calculate Profit Per Job: A Simple Guide for Contractors

Most contractors run their business by checking the bank account. Money comes in, money goes out. If there is cash left at the end of the month, they assume they made money. The problem? They have no idea which jobs actually generated profit and which ones cost them money.

A plumbing contractor who charges $5,000 for a bathroom rough-in might feel like they had a good month. But after labor, materials, sub costs, and three return trips for punch-list fixes, that job might have made $200. Or lost $300. Without per-job profit tracking, they will never know — and they will keep bidding the same way.

Here is exactly how to calculate profit per job, even if you have never tracked costs before.

Step 1: List Every Direct Cost

Direct costs are everything you spent specifically for this job. If the job did not exist, this money would not have been spent. Break it into:

• Materials: All materials and supplies purchased for this job. Include the small stuff — fasteners, adhesives, blades that wear out, protective gear. It adds up fast. Add 8-12% waste factor on top of material totals.
• Labor (yours): Your hourly rate times actual hours worked. Include setup time, cleanup, material runs, and drive time to and from the site. Most contractors undercount their own hours by 20-30% because they skip the small time blocks.
• Labor (crew): Employee wages, payroll taxes, workers compensation, benefits. A $25/hour employee actually costs $32-38/hour after burden. Use the loaded rate, not the base wage.
• Subcontractors: Their invoice amount plus any markup or management time you spent coordinating them. If you spent two hours on the phone fixing a sub scheduling issue, that goes on this job.
• Equipment and rentals: Dumpster fees, equipment rental, tool purchases specifically for this job, fuel for generators and equipment.
• Permits and fees: Building permits, inspection fees, disposal fees, any compliance costs tied to this specific job.

Step 2: Allocate Overhead

Overhead is the cost of being in business regardless of any specific job. It includes insurance, office rent, vehicle payments, bookkeeping, software subscriptions, marketing, phone bill, and general tools not tied to a single job.

There are two ways to allocate overhead per job. The simple way is a percentage. Take your total annual overhead and divide it by your expected annual revenue. If your overhead is $36,000 and you expect to do $240,000 in revenue, your overhead rate is 15%. Add 15% of every job quote to cover overhead.

The more accurate way is a daily rate. Take your annual overhead and divide by the number of working days per year — typically 220-240 after holidays, sick days, and weather days. If overhead is $36,000 and you work 230 days, overhead costs you $156 per working day. A 5-day job carries $780 in overhead allocation.

Step 3: Subtract All Costs from Revenue

Now the math is simple:

Then calculate profit margin: (Job Profit / Job Revenue) x 100. A $10,000 job that costs $7,500 total leaves $2,500 profit — a 25% margin.

Step 4: Compare to Your Estimate (Every Time)

This is the step that separates profitable contractors from broke ones. After every job, put your actual costs next to your original estimate and write down why each variance happened.

You will quickly spot patterns:

• Labor hours are consistently 20% over estimate on bathroom remodels
• Material waste is higher when you buy from Supplier A vs Supplier B
• Certain subs always come in 10% over their quote
• Drive time on rural jobs eats 3% more margin than you planned

After 10-15 jobs tracked this way, your estimates become predictions. You will know exactly which types of work make money, which clients are worth it, and what your real break-even rate is. This data is worth more than any pricing guide book.

Common Mistakes

• Forgetting your own labor. Your time is not free. If you do not pay yourself an hourly rate on every job, you are not calculating real profit. You are just tracking how much cash went through your hands.
• Mixing jobs together. Some contractors pool all job costs and revenue together and look at monthly totals. This hides the losers. One profitable job can mask three that lost money.
• Ignoring change orders. If the customer asks for extra work mid-job, track it as a separate line item. Scope creep is the number one silent margin killer in construction. Treat every change as its own mini-job with its own costs.
• Skipping overhead. Insurance, vehicle, tools, office — these are real costs. If you do not allocate them to jobs, your per-job profit numbers will look better than reality. That leads to overconfident pricing and slow cash bleed.
• Not tracking consistently. Doing this for two jobs and then stopping is the same as not doing it at all. Make it a habit. Five minutes after every job to log the numbers. The habit matters more than the tool.

What Tool Should You Use?

A spreadsheet works. A notebook works. What matters is that you actually do it. But if you want something simpler:

• Spreadsheet (free): Create columns for each cost category and update manually. Works fine if you are disciplined. Breaks down when you get busy and fall behind on data entry.
• QuickBooks (starts at $35/mo): Handles overall accounting but is not designed for per-job profitability. You have to set up classes or projects and it gets fiddly for a solo contractor.
• Full construction ERP ($50-500/mo): Procore, JobTread, Contractor Foreman — these are built for mid-size and large contractors with crews, project managers, and complex scheduling. If you are a solo operator or small crew, 80% of the features are overkill.
• ProfitScope ($12/mo): Built specifically for service contractors who just need to see profit per job. Put in your rate, hours, materials, and subs — it shows profit and margin instantly. No accounting degree required.

The Bottom Line

Calculating profit per job is not complicated. It is four steps: list direct costs, allocate overhead, subtract from revenue, compare to your estimate. The hard part is not the math — it is building the habit of actually doing it after every job.

The contractors who track per-job profit bid more confidently, lose less on change orders, and know exactly which jobs to take and which to walk away from. The ones who do not track keep guessing — and guessing is expensive.