Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Bay utilization
63.3%
Total bay-hour capacity
1,500
Idle bay-hours per month
550
Unrealized labor revenue per month
$71,500
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How to use this
- 1Enter number of service bays.
- 2Enter hours open per day (hrs).
- 3Enter days open per month.
- 4Enter total billed hours per month (hrs).
- 5Enter effective labor rate ($/hr).
- 6Read your bay utilization on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
A shop's real capacity ceiling is bay-hours, not technician headcount — you can hire another tech, but if there's no open bay, that hire adds nothing. Bay utilization measures actual billed hours produced against the total hours each bay is open and staffed, exposing whether growth needs another bay, another shift, or just better scheduling to close the gap between open hours and billed hours. This calculator takes bay count, operating hours, and hours actually billed through those bays to compute utilization percentage and the revenue you're leaving on the table if a bay sits idle waiting on tows, parts, or diagnostics instead of turning cars. Most shops discover 15-30 unbilled bay-hours a week hiding in idle time once they actually measure it, which at a modest labor rate is thousands of dollars of unrealized capacity monthly without adding a single square foot.
Worked example
Using the values the calculator loads with:
Inputs
- Number of service bays: 6
- Hours open per day: 10 hrs
- Days open per month: 25
- Total billed hours per month: 950 hrs
- Effective labor rate: 130 $/hr
Results
- Bay utilization: 63.3%
- Total bay-hour capacity: 1,500
- Idle bay-hours per month: 550
- Unrealized labor revenue per month: $71,500
What each field means
Inputs
- Number of service bays
- The number of service bays used in the calculation. Starts at 6 so you have a working example on load.
- Hours open per day (hrs)
- The hours open per day used in the calculation, measured in hrs. Starts at 10 hrs so you have a working example on load. Accepted range: 1–24 hrs.
- Days open per month
- The days open per month used in the calculation. Starts at 25 so you have a working example on load. Accepted range: 1–31.
- Total billed hours per month (hrs)
- The total billed hours per month used in the calculation, measured in hrs. Starts at 950 hrs so you have a working example on load.
- Effective labor rate ($/hr)
- The effective labor rate used in the calculation, measured in $/hr. Starts at 130 $/hr so you have a working example on load.
Results
- Bay utilization
- Returned as a percentage and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total bay-hour capacity
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Idle bay-hours per month
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Unrealized labor revenue per month
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What utilization percentage is realistic?
75-85% is a strong target. 100% isn't achievable or even desirable because you need slack for diagnostics, comebacks, and same-day emergency work. Below 60% consistently signals either a marketing/car-count problem or a scheduling inefficiency, not a capacity problem.
Should lift/alignment bays count the same as general bays?
No, model them separately if they have different throughput. An alignment bay might turn 3-4 cars a day at 45 minutes each while a general repair bay holds one car for hours; blending them into one utilization number hides which bay type actually needs investment.
How does this relate to hiring another technician?
If utilization is already above 85% and idle hours are low, a new tech has nowhere to work — you need another bay or a second shift before another hire helps. If utilization is below 70%, the bottleneck is car count or scheduling, and another tech won't fix it either.
What causes idle bay-hours most often?
Parts delays, waiting on customer approval for additional work, poor appointment spacing that leaves gaps, and technicians pulled off jobs for shuttle runs or counter help. Tracking idle time by cause for two weeks usually reveals one dominant culprit.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Bay Utilization Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/bay-utilization
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/bay-utilization" target="_blank" rel="noopener">Bay Utilization Calculator — RevenueLab</a> (2026).</p>
Source: [Bay Utilization Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/bay-utilization) (2026).