Contractor Time Tracking: Compare Estimated Hours With Actual Job Hours
Comparing estimated and actual hours reveals a variance to investigate, not a verdict. It tells you about the labor-hour assumption, and nothing on its own about whether the job made money.
The assumptions
This model assumes
- An isolated illustrative job, not derived from the published solo model
- A $6,000 labor price component covering 100 estimated hours
- The same approved scope takes 125 actual hours; no change order was added
- Figures are hourly revenue from a fixed labor price, not wages, cost or profit
- The published model's annual figures, 2,080 compensated hours with 1,332 billable and a $132.80 rate, are a separate calculation this article does not revise
The model, step by step
Start by defining which hours belong in the comparison. This precedes any tool.
A job consumes more than site presence: job-specific purchasing and travel, off-site fabrication, planning and customer coordination, and rework or callbacks. Meanwhile presence on a site is not automatically productive labor. Breaks, a timer left running, and a departure that was never recorded all inflate it.
So automatic site detection measures presence, not labor, and it cannot classify hours for you.
| Category | What belongs in it |
|---|---|
| Attributable to a specific job | Production, and any job-specific work you have decided to count |
| Business time, no job | Estimating, admin, travel that belongs to no single job |
| Compensated but not worked | Reconciled separately; job and business timers do not record it |
An automatically detected session arrives flagged for review and is not counted until you confirm it. You decide whether the visit was work, which job it belonged to, and how many of those hours were actually labor.
Corrections do not overwrite. Editing an entry writes a new record that supersedes the previous one, with the capture source left read-only, so a corrected figure carries its own history. Totals resolve to the head of each correction chain, so a corrected entry contributes once rather than twice.
In this isolated example the approved labor scope is unchanged: a $6,000 labor price component covering 100 estimated hours, and the same scope takes 125 hours.
The comparison must run against the currently approved scope, with the original kept as a baseline. Otherwise a properly priced change order makes a well-run job look like an estimating failure: you added scope, the customer paid for it, the hours went up, and a naive comparison calls that a miss.
When scope changes are approved, update both the labor price component and the estimated-hour allowance before comparing them with actual hours, and retain the original figures to show how the job evolved. Approving a change order does not by itself create an hour allowance; that allowance has to exist internally for this comparison to mean anything.
A 25-hour overrun is one number with several possible causes, and they call for different responses.
| Cause | Response |
|---|---|
| The original scope was underestimated | Fix the estimate |
| Scope was added and approved | Compare the added hours against the change order's own estimated hours and price. Approval alone does not establish it was priced adequately |
| Scope was added and never priced | Fix the change order habit, not the estimate |
| Rework or a callback | Fix the process |
| Travel or purchasing the estimate never included | Fix what the estimate covers |
| The time records are wrong | Fix the records before concluding anything |
The published model's $132.80 an hour depends on annual assumptions about compensation, overhead and billable hours. A single overrun does not establish a new required rate.
What one job can and cannot revise
| Whether this job's labor-hour estimate was right | Yes |
| Whether scope grew without being priced | Yes |
| Whether the annual required rate should change | No |
| Whether the job made money | No, that needs full job costing |
| Hours alone establish | the labor-hour assumption, nothing more |
It can justify revisiting the forecast if it reveals a recurring omission or a material change in expected capacity. Use comparable jobs and the remaining work schedule to assess that, rather than waiting for year-end. The reverse error is just as common: a job that comes in under its estimate does not prove the rate is too high.
What it means
Have an hours assumption to compare against
Clamp records time against the job that caused it, keeps business time separate, and holds automatically detected visits for review before they count. Corrections supersede rather than overwrite, so a figure you changed still shows what it was.
Pick one finished job. Write down the hours its labor price assumed, then the hours it actually took on the scope that was finally approved. If those differ, work the six causes before changing a price. To have an hours assumption worth comparing against, the estimate has to state one in the first place.
Sources & provenance
- The Hourly Rate a Solo Contractor Needs to Make $100,000 Clamp (owner-supplied)