Labor Time Estimator from Flat-Rate Guide and Shop History
Takes the flat-rate guide times the owner or service writer types in, compares them with how long the shop actually took on similar jobs, and produces a labor hour estimate with a clear reason for each line.
Before and after
Labor estimate: 2014 Chevrolet Silverado 1500, 5.3 engine, 163,000 miles
Jobs and times
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Water pump
- Guide: 2.6 hours
- Shop history: average 2.5 hours across 4 jobs (2.2, 2.5, 2.8, 2.5; total 10.0 divided by 4)
- Recommended: 2.6 hours. History is within 15 percent of the guide, so we recommend quoting the guide time.
- Dollars: 2.6 x 140 = $364.00
-
Serpentine belt
- Guide: 0.4 hours
- Shop history: usually 0.3 hours (no job count given, so treat as an informal figure)
- Recommended: 0.4 hours. We recommend the guide time because the history is not backed by a job count.
- Dollars: 0.4 x 140 = $56.00
- Note: you said the belt has to come off for the pump. You did not say whether the guide already counts that, so see the confirm list.
-
Thermostat
- Guide: 1.1 hours
- Shop history: average 1.1 hours across 2 jobs (1.0 and 1.2). History is thin.
- Recommended: 1.1 hours, the guide time.
- Dollars: 1.1 x 140 = $154.00
Adjustments
- Shared labor with the water pump: minus 0.5 hours, as you described (-0.5 x 140 = -$70.00)
- Rust and seized bolts allowance: plus 0.5 hours, as you described (0.5 x 140 = $70.00)
Totals
- Guide-based jobs: 2.6 + 0.4 + 1.1 = 4.1 hours
- Adjustments: minus 0.5 plus 0.5 = 0.0 hours
- Total labor to quote: 4.1 hours
- At $140 per hour: 4.1 x 140 = $574.00
Confirm before quoting
- Does the guide already include belt removal in the water pump time? If yes, the belt may be a double charge, and we recommend removing its 0.4 hours (total would be 3.7 hours, or $518.00).
- Is the 0.5 shared labor between the pump and thermostat already built into the guide's thermostat time? If so, do not subtract it again.
- The rust allowance is a guess. We recommend telling the customer it may change if bolts break, and getting approval before adding time.
- Confirm any local rules on written estimates and customer approval before sending.
What it does
Takes the flat-rate guide times the owner or service writer types in, compares them with how long the shop actually took on similar jobs, and produces a labor hour estimate with a clear reason for each line. It flags overlapping labor so the customer is not charged twice for the same work.
Use it when: Use when an auto repair shop needs to build a labor time estimate for a job from flat-rate guide entries and the shop's own history, such as "how many hours should I quote," "estimate the labor on this," "what's the book time," or "how long does this usually take us."