A separate spreadsheet can actually work well when the goal is to see profitability across multiple jobs in one place.
The key for me is not just calculating profit after a job is finished. I want to compare the original estimate and target margin against actual labor, materials, subcontractor costs, change orders, and payments while the job is still active.
That way you can see cost variance and projected final profit early enough to do something about it.
For a small contractor who doesn't need a full accounting or project management system, Excel can be a practical way to build that visibility.
